20070319
38．A．safety B．health C．danger D．life
39．A．observed B．realized C．found D．thought
40．A．pushed B．opened C．locked D．fixed
第二部分 閱讀理解:（共兩節(jié), 滿分50分）
第一節(jié)（共20小題; 每小題2分, 滿分40分））閱讀下列短文, 從每題所給的選項（A、B、C和D）中，選出最佳選項，并在答題卷上將該項涂黑。
A
Friendlies
abandoned as name for mascots(吉祥物)
The name
"Friendlies" has been abandoned as the organization committee for the
2008 Beijing Olympics silently changed the English
name of the Games' five mascot dolls last week. The organization committee
decided to adopt the name "Fuwa", which is a pinyin translation of
its Chinese name and is more frequently used in China.
However, the
organization committee replaced all Friendlies to Fuwa on its official site,
but without giving a formal announcement to inform the public of the change. It
is said that they received an inside notice about the change last week but
don't want to emphasize it for fear of affecting the sales of Olympic goods.
Li Yanjun, a
Legal Affairs Department official, said the decision was made considering a
variety of reasons but did not want to comment on them. "You may know
about the background and many unfavorable comments concerning the mascots'
former name across the web, but I won't comment on them," Li said. "I'm
not in the position to make it clear if the change was caused by this."
A report
published last week on China Radio International (CRI)made the name change known
and listed the reasons why the Friendlies name should be changed.
"Firstly, Friendly is somewhat an unclear name, which could refer both to
friendly people and friendly matches,"a Dr. Li from Lanzhou University
was quoted as saying on the site. "Secondly, the term Friendlies has a
similar pronunciation to 'friendless' and thirdly, the spelling of Friendlies
could be split as 'friend lies'."
Laura Fitch, a
Canadian who works in China
as news editor, welcomed the change, saying the name Friendlies sounds a
"a little bit childish" and "doesn't really have a
meaning."
41. why did the organization committee change
the name “Friendlies” into “Fuwa” without giving a formal announcement?
A. Because it is
not important to make it known.
B. Because
everybody will know it by surfing the internet.
C. Because it
will perhaps affect the sales of Olympic products.
D. Because all the
people will criticize them for changing its name.
42. Which of the following is not true as the
reasons for changing the name?
A. Friendly is a name with
more than one meaning.
B. It is very easy for
people to pronounce the name in a wrong way.
C. People are likely to
split it as “Friend lies”.
D. “Friendly” is not a
suitable name for Olympic goods.
43. What can be inferred from what Li
Yanjun said in Para.3?
A.
He liked the name while others didn’t.
B.
He didn’t know how to comment on unfavourable comments.
C.
It is likely that the change of the name was caused by the unfavourable
comments.
D.
People would not make unfavourable comments on “Friendlies” if they knew about
the background.
44. What’s the people’s reaction to the
change of the name according to the last paragraph?
A.
approving B.
exciting C.
dislike D. not
mentioned
B
This
is a doubtful age, but although our faith in many of the things has weakened,
our confidence in the curative (治療，藥物) properties of the bottle medicine remains the same. This modern
faith in medicine is proved by the fact that the annual drug bill of the Health
Services is increasing to huge figures and shows no signs at present of stopping
to rise. The majority of the patients attending the medical out-patients(門診病人) departments of our hospitals
feel that they have not received enough treatment unless they are able to carry
home with them some tangible(有形的) curative in the shape of a bottle of medicine, a box of pills, or
a small jar of ointment(軟膏), and the doctor in charge of the department is only too ready to
provide them with these requirements. There is no quicker method of treating of
patients than by giving them what they are asking for, and since most doctors
in the Health Services are overworked and have little time for offering
time-consuming and little-appreciated advice on such subjects as diet, right
living, and the need for abandoning bad habits etc.
Nor is it only
the ignorant and ill-educated person who has such faith in the bottle of
medicine. It is said that Thomas Carlyle (a famous Scottish writer), when he
heard of the illness of his friend, went off immediately to visit him carrying
with him in his pocket what remained of a bottle of medicine formerly used for a
slight illness of Mrs. Carlyle’s. Carlyle was entirely ignorant of what the bottle
in his pocket contained or the nature of the illness from which his friend was
suffering, but a medicine that had worked so well in one form of illness would
surely be of equal benefit in another, and comforted by the thought of the help
he was bringing to his friend, he rushed to Henry Taylor’s house. History does
not relate whether his friend accepted his medical help, but probably he did.
45.
According to the author,
patients feel that they have been properly treated only if they _____.
A.
can take home some medicine
doctors give them
B.
have confidence in the curative
properties of a bottle of medicine
C.
are given careful check-ups by
doctor
D.
are offered advice on diet and
living by the doctor
46.
It can be learned from the
passage that most doctors ________.
A.
feel morally bound(有義務(wù)的) to give patients advice about
diet and right living
B.
are reluctant to provide
patients with their requirements
C.
are confident in the curative
properties of the bottle of medicine
D.
tend to satisfy patients’
demand for tangible medicine
47.
The story about Thomas Carlyle
is used to illustrate that _________.
A.
a medicine that will cure one
illness is not necessarily good for another
B.
Thomas Carlyle was ignorant
C.
Even educated people can be
misled into believing that one can’t be cured by medicine
D.
Educated people may also have
confidence in the bottle of medicine
48.
The passage mainly tells us
that _________.
A.
we are in a skeptical age
B.
people’s faith in the bottle of
medicine has not weakened in the modern age
C.
there are some problems in
modern medical service
D.
patients have a tendency to put
their own will on doctors
C
LAST week's
decision by the International Astronomical Union (IAU) to strip
Pluto(冥王星) of
its planetary status, held since its discovery in 1930, has made a lot of
people sad. "Pluto," American science writer Dava Sobel writes in her
book “The Planets”, “still has an emotional hold on planethood. People love
Pluto. Children identify with its smallness. Adults felt it hard to accept its
isolated existence.”
Many people felt
sorry about Pluto's demotion（降級）. “I just cannot accept this at this time,” says Liu Ming, 29, who runs
a small company in Shanghai.
“I was taught that 'the Nine Great Planets’ formed our solar system since
primary school. And now they suddenly decrease the planets to eight. This will
take some time for most of us to absorb it,” says Liu.
Ordinary people are
simply not used to it, but for some professionals, especially the persons in
charge of planetariums(天文館) and educators, the change has become a real headache. The “eight
instead of nine” change will affect thousands of planetariums around the world.
Schools will also be greatly affected.
In
China,
teachers are anxious as outdated textbooks are printed and given out to the
remotest corner of the country for school children ready to start a new term
soon. According to the Ministry of Education, new textbooks with changed
contents will not be available until next year.
Zhao Zhiheng, a
member of the Astronomy Association from Tianjin,
suggested that primary and middle school teachers be trained in the improved
knowledge, and that the media carry more stories to let people know about the
change as soon as possible.
49.
The underlined phrase “strip…of”
in paragraph1 means “__________”.
A. take…away
from B.
mark…with
C. get…ready for D. push…into
50. What’s the feeling of ordinary people
to the change?
A.
They thought it necessary to have a change.
B.
They accepted it without hesitation.
C.
They felt a little sad and not used to it.
D.
They were strongly against the change.
51. Why did the change affect schools
greatly?
A.
Teachers disagreed with the change and refused to accept it.
B.
Schools had to spend a lot of money on books.
C.
Students do not like the change of it.
D.
New textbooks will not be ready so soon.
52. In the following suggestions, which one
is made by Zhao Zhiheng?
A.
Planetariums around the world should adapt to the change quickly.
B.
The media should make it known to people as soon as possible.
C. Teachers needn’t be trained in improved knowledge as soon as
possible.
D.
Schoolchildren should be ready for the new knowledge.
D
A WOMAN walks
into a small stall and eats a cheap bowl of instant noodles, paying 1,500 won.
Then she moves into a Starbucks coffee shop, where she drinks a cup of mocha,
paying 4,300 won.
Surprised? This
is the typical behaviour of South Korean young women. They are called
"denjang girls". The term "denjang girls" referred to
female shoppers who would eat cheaply and then splash out to be
seen drinking a cup of expensive coffee. Now it has grown to a new army of
women in their 20s who look smart, rich but are actually buying luxuries they
probably can't afford.
Internet users created
the term when debating the popularity of Starbucks coffee among South Korean
women. In South Korea, the
coffee costs, on average, over a dollar more than in Japan
and the US.
Despite the higher price, Starbucks sales in South Korea increased from 72.1
billion won in 2004 to 91.2 billion won in 2005.
Ahn Ji-Yoon, a
student at Yonsei University in Seoul,
says she can spend two hours surfing the web for discounts on skin cream and
dinner. Yet she would think nothing of spending US$550 on a Gucci bag. Girls
like Ahn live by extremes - hunting for bargain items while spending heavily on
"necessary luxuries".
53. The underlined part in paragraph 2
means _____________.
A.
give away B.
use…in a carefree way
C.
make good use of D.
use up
54. What does the term “denjang girls”
refer to?
A.
It refers to female shoppers who eat cheaply.
B.
It refers to female shoppers who drink expensive coffee.
C.
It refers to female shoppers who eat cheaply and spend little in drinking a cup
of cheap coffee.
D.
It refers to female shoppers who eat cheaply but spend a lot in drinking a cup
of expensive coffee.
55. According to the passage , which one is
correct?
A.
In South Korea, the coffee costs more than in Japan
and the US.
B.
In South Korea, the coffee costs less than in Japan
and the US.
C.
In Japan, the coffee costs a little more than in South
Korea and the US.
D.
In the US, the coffee costs
a little more than in South Korea
and Japan.
56. The purpose of the writer is to
_________.
A.
criticize the manners of “denjang girls”
B.
call on female shoppers to act like “denjang girls”
C.
warn “denjang girls” not to waste money on expensive coffee.
D.
introduce new female shoppers “denjang girls” in South Korea.
E
College students go ‘blind
for a day’
A group of 18 students at the leshan Teachers’ College
experienced the hardships of the vision damaged during a “blind for a day”
exercise over the weekend. The college’s Department of Education organized the
event, aiming to give students an understanding of the daily battle faced by
the vision damaged so that they may offer their help in the future.
Taiyuan forbids taking pets into its parks
The local government of Taiyuan has banned pets from being taken into
the city’s parks. The regulation, which came into effect on Saturday, states
that anyone who takes pets into parks will be fined from 10 yuan (US$1.27) to
200(US$25). The local government said it introduced the rule because pets may
cause harm to other park visitors and their waste pollutes the environment.
Enormous pumpkin steals
the show
A 240-kilogram pumpkin worth over 2,300 yuan
(US$293) was the star attraction at an agricultural show in Foshan’s Shunde
District over the weekend. Visitors all wanted to have their pictures taken
with the huge pumpkin at the first Guangdong Agricultural Products Fair. The
pumpkin was planted by the Zhuhai Academy of Agriculture Science.
More than 1,000 seagulls
die on beach of Shandong
More than 1,000 seagulls died on the beach in Jimo, Shandong
Province, last week. Experts investigating the case stressed that the cause of
death was not bird flu. They said the seagulls died from a disease, but they
are still testing samples to determine which one.
57. The aim of the event “blind for a day” is to
_________.
A.
give the students a lesson about the hardships of the vision damaged
B.
entertain the students after regular lessons
C.
urge the students to take part in the social activity
D.
make the students understand the blind people and offer help in the future
58. Taiyuan
government banned pets from getting into parks because _________.
Which of the following is wrong?
A. Pets may cause harm to other park visitors
B. Pets’ waste pollutes the environment
C. A person who takes pets into park will be fined US$ 1.
D. The government wants to protect the environment
59.Why did the pumpkin become the star attraction?
A. Because it was worth over 2,300 yuan.
B.
Because a
lot of people want to take pictures with it.
C.
Because
it is a new product planted by the Zhuhai Academy of Agriculture Science.
D. Because it weighed 240-kilogram
60. The cause of the seagull death in Shandong Province is ____________.
A.
bird flu B.
an unkown deadly disease C. air
pollution D. cold
weather
第二節(jié)：閱讀下列材料，并從所給的六個選項（A、B、C、D、E和F）中選出符合各小題要求的最佳選項。選項中有一項是多余選項。
The people below are going
to make a trip in Australia.
After the description of these people, there is information about six
advertisements of organized tours A-F. Decide which tour would be most suitable
for the person mentioned in descriptions 61-65 and then mark the correct letter
(A-F). There is one extra paragraph about one tour which you do not need to
use.
_________61. Victor is fond of nature and adventure
and he is making a study tour into geology in Australia. So he wants to make a
whole day trip, enjoy the natural beauty and study geological phenomena as
well.
_________62. Vanessa is planning a short city tour
of Sydney so that she can enjoy the highlights
of the city and attend an important lecture given by Professor Brown Smith at
2:00p.m at the University
of Sydney.
_________63. Charlie and his friends are making
their first journey in Australia.
Having traveled around the city of Sydney, they
plan to visit Canberra,
the capital and political center of the country.
_________64. Jenny, a European woman with her
children is visiting her relatives in Australia. They want to relax
themselves by enjoying the sunshine on the sandy beaches along the coast and
have fun with dolphins.
_________65. Mike and Susan are from Brazil. They
have been traveling in Australia
for a couple of days. This weekend, they would like to have a change and travel
to the countryside to have some idea of Australia grape farming and wine
producing instead of making city tours around.
A. City Highlights,
Manly Beach, Northern Beaches
Tour the highlights of Sydney,
then cross the Sydney Harbor Bridge
to Manly and the Northern
Beaches. Capture the
beauty and lifestyles of the harbor city form Gray Line’s specially selected
points.
Departs: 8:30 a.m. Adult: $51.00
Returns: 11:50 a.m. Child: $25.50
B. New Parliament
House, National Museum, Australian War Memorial
The nation’s capital―a purposely built city, modern,
with wonderful architecture yet a rural charm of lakeside, gardens and open
spaces. This hi-tech city is the seat of Parliament and home of national
monuments, museums and galleries.
Departs: 8:30 a.m. Adult: $110.00
Returns: 9:15 p.m. Child: $55.00
C. Cuddle a
Koala, Kangaroos, Harbour Luncheon Cruise
Observe and meet our unique native animals with a
lot of opportunities to get to know the Cuddly Koala. Then enjoy lunch on
beautiful Sydney Harbour. You can choose between the
Matilda Cruises Sailing Catamarans, the stream-lined Captain Cook Cruisers or
Magistic Cruises.
Departs: 8:40 a.m. Adult: $115.00
Returns: 2:00 p.m. Child: $57.50
D. Hunter Valley
wine factory, Wine Tasting, Traditional
Aussie Towns
It is believed that famous Australian wines are from
the vineyards of the rolling hills and valleys’ of the Hunter region. The Hunter Valley
is Australian’s oldest commercial wine producing district with over 7,000 acres
under vine.
Departs: 8:40 a.
m Adult: $127.00
Returns: 6:40 p.m Child: $63.50
E. Post
Stephens, Central Coast Beaches, North
Coast, Dolphin Watching
Discovering the beautiful Central
Coast north of Sydney
with its holiday villages, white sandy beaches and the sparkling Pacific Ocean. Ride the wave crests with the Dolphins in
the blue waters. This quiet arm of the blue Pacific Ocean
is home to nature’s most lovable and intelligent marine mammals.
Departs: 8:30 a.
m. Adult: $126.00
Returns: 7:00 p. m. Child:
$ 63.00
F. Jenolan Caves,
Blue Mountains, Adventure
Caves
The Blue Mountains National Park is a kaleidoscope(萬花筒) of contrasts and colour rich in
Australian bush and wildlife. Spectacular
Jenolan Caves―the
brilliance and timelessness of nature are revealed.
Departs: 8:40 a.
m. Adult:
$114.00
Returns: 6:40 p. m. Child:
$57.00
第Ⅱ卷（共50分）
第三部分：寫作（共三節(jié)，滿分50分）
第一節(jié) 單詞拼寫: （共10小題；每小題1分，滿分10分）
66. After high school, Jim hopes to go to c___________
to take courses in art.
67. The Browns had no children so they a___________
a baby.
68. He never tells lies, so he is well-known for his
h___________.
69. I s_________ a house with four other people.
70. Danny feels that they should have father’s
p___________ before going out.
71. Although he left school more than ten years ago,
he still keeps in touch with his f__________ classmates.
72. Stories of Helen Keller opened up a new world to
the people with d____________.
73. It’s hard to get the villagers together because
they live s______________.
74. F____________, a kind and brave peasant passed
there and saved the wounded soldier.
75. Don’t be d____________. Failure is the mother of
success.
第二節(jié) 短文改錯（共10小題；每小題1分，滿分10分）
此題要求改正所給短文中的錯誤。對標(biāo)有題號的每一行作出判斷：如無錯誤，在該行右邊橫線上畫一個勾（√）；如有錯誤（每行只有一個錯誤），則按下列情況改正：
該行多一個詞：把多余的詞用斜線（\）劃掉，在該行右邊橫線上寫出該詞，并也用斜線劃掉。
Last week I went to a movie, which was very
touched. It was a sad 1. .
movie about a mother and her sons. When the
child was a little 2. .
boy, his mother was very poor that she had
to send him to a rich 3.
family who had no child. The boy received a
very good education 4.
.
and twenty years later he became doctor. In
his hospital, he had a 5. .
patient, who was an old lady. He did care
too much about her, 6. .
for she could hardly afford for the medical
care . One evening, the 7. .
lady died quietly of a serious illness but
on her bed the doctor found 8. .
a letter, in it he discovered the truth and
felt the love of a great 9. .
mother. He had wanted to call her mother,
but it was too late . 10.
.
Everybody in the theatre was moved to tears.
第三節(jié)：書面表達(dá)（滿分30分）
你校正在開展創(chuàng)建節(jié)約型校園的活動。可是你發(fā)現(xiàn)你校校園內(nèi)的浪費現(xiàn)象嚴(yán)重。請你根據(jù)下表所列內(nèi)容給校報寫一篇小短文（詞數(shù)120），反映現(xiàn)象，敘述后果，提出建議，提倡從我做起，建設(shè)節(jié)約型校園。
現(xiàn)象
長流水
長明燈
餐桌上剩余的食物
隨處可見的廢紙
后果
浪費有限的資源
養(yǎng)成不良的習(xí)慣，不利于品德養(yǎng)成
增加學(xué)校開支，增加父母親的經(jīng)濟(jì)負(fù)擔(dān)
建議
至少兩條
開頭句已經(jīng)給出不計入總詞數(shù)內(nèi)。resources-saving節(jié)能的, expenditure支出, 花費
Nowadays,
our school is calling on us to create a resources-saving
campus.
2007年溫州中學(xué)高三第三次模擬考英語答題卷
任務(wù)型閱讀：（每小題2分，共10分）
61._________ 62._________ 63._________ 64._________ 65._________
單詞拼寫：（每小題1分，共10分）
66._______________ 67._______________ 68.______________ 69._______________
70._______________ 71._______________ 72.______________ 73._______________
74._______________ 75._______________
短文改錯（共10小題；每小題1分，滿分10分）
此題要求改正所給短文中的錯誤。對標(biāo)有題號的每一行作出判斷：如無錯誤，在該行右邊橫線上畫一個勾（√）；如有錯誤（每行只有一個錯誤），則按下列情況改正：
該行多一個詞：把多余的詞用斜線（\）劃掉，在該行右邊橫線上寫出該詞，并也用斜線劃掉。
Last week I went to a movie, which was very
touched. It was a sad 1. .
movie about a mother and her sons. When the
child was a little 2. .
boy, his mother was very poor that she had
to send him to a rich 3.
family who had no child. The boy received a
very good education 4.
.
and twenty years later he became doctor. In
his hospital, he had a 5. .
patient, who was an old lady. He did care
too much about her, 6. .
for she could hardly afford for the medical
care . One evening, the 7. .
lady died quietly of a serious illness but
on her bed the doctor found 8. .
a letter, in it he discovered the truth and
felt the love of a great 9. .
mother. He had wanted to call her mother,
but it was too late . 10.
.
Everybody in the theatre was moved to
tears.
書面表達(dá)（滿分30分）
你校正在開展創(chuàng)建節(jié)約型社會的活動。可是在日常生活中你發(fā)現(xiàn)你校校園內(nèi)的浪費現(xiàn)象嚴(yán)重。請你根據(jù)下表所列內(nèi)容給校報寫一篇小短文（詞數(shù)120），反映現(xiàn)象，敘述后果，提出建議，提倡從我做起，建設(shè)節(jié)約型校園。
現(xiàn)象
長流水
長明燈
餐桌上剩余的食物
隨處可見的廢紙
后果
浪費有限的資源
養(yǎng)成不良的習(xí)慣，不利于品德養(yǎng)成
增加學(xué)校開支，增加父母親的經(jīng)濟(jì)負(fù)擔(dān)
建議
至少兩條
開頭句已經(jīng)給出不計入總詞數(shù)內(nèi)。resources-saving, expenditure支出, 花費
Nowadays, our school is calling us to
create a resources-saving campus.
2007年溫州中學(xué)高三第三次模擬考英語答案
單項填空：20分
CDDCA
ADCAA DBCBD BABCB
完型填空：30分
BADBC
ADCBA CDBBA CDADC
閱讀理解： 40+ 10分
CDCA
ADDB ACDB BDAD DCDB 61―65 FABED
單詞拼寫 10分
66. college
67. adopted 68. honesty 69. share 70. permission
71. former
72. disability 73.
separately 74. Fortunately
75. discouraged
短文改錯 10分
76. touched→touching 77. sons→son 78. very→so 79. √ 80. became∧→a
81. did→didn’t或在did∧→not 82. 第二個for去掉83．but→and
84．it→which 85．had去掉
書面表達(dá) 30分
One possible
version
Nowadays, some
of us students have formed some bad habits on campus. For example, some students leave the lights on in the
daytime, or let water running after washing. Some leave over much food on the
table after eating. Besides, waste paper can be seen everywhere.
It is well know
that these bad habits will have a bad influence on our character and behavior.
What’s worse, they can not only increase our cost at school and add financial
burden to our parents, but also waste the limited resources.
So to build a
resources-saving campus it is high time that we had to deal with the problems. In
my opinion, we should start with ourselves to save everything. I'd like to
remind my classmates to take the lead in reducing the waste. We must form some
good habits. For example, when we brush our teeth and wash hands, never leave
water running unnecessarily and when we leave classrooms, we should make sure
that the lights have been turned off.
試題詳情
R2
R2
13．如圖所示，帶有活塞的氣缸中封閉一定質(zhì)量的氣體（不計氣體的分子勢能以及氣缸壁和活塞間的摩擦）。將一個半導(dǎo)體NTC熱敏電阻R（隨著溫度的升高熱敏電阻阻值減小）置于氣缸中，熱敏電阻R與氣缸外的電源E和電流表A組成閉合電路，氣缸和活塞具有良好的絕熱性能。若發(fā)現(xiàn)電流表的讀數(shù)增大，以下判斷正確的是
14．一理想變壓器，原、副線圈的匝數(shù)比為4∶1。原線圈接在一個交流電源上，交變電壓隨時間變化的規(guī)律如圖所示。副線圈所接的負(fù)載電阻是11Ω。則下列說法中不正確的是
A．在α粒子散射實驗的基礎(chǔ)上盧瑟福提出了原子的核式結(jié)構(gòu)模型
17．如圖，真空中O點有一點電荷，在它產(chǎn)生的電場中有a、b兩點，a點的場強(qiáng)大小為Ea，方向與ab連線成60°角，b點的場強(qiáng)大小為Eb，方向與ab連線成30°角。關(guān)于a、b兩點場強(qiáng)大小Ea、Eb及電勢Φa、Φb的關(guān)系，以下結(jié)論正確的是
Eb，Φa<Φb
B．月球的質(zhì)量為
D．月球運動的加速度為
20．放在水平地面上的物體受到水平拉力的作用，在0~6s內(nèi)其速度與時間圖象和拉力的功率與時間圖象如圖所示，則物體的質(zhì)量為（取g=
B．
D．
A．分劃板的中心刻線分別對準(zhǔn)第1條和第4條亮紋的中心時，手輪上的讀數(shù)如圖3所示，則對準(zhǔn)第1條時讀數(shù)x1=________mm，對準(zhǔn)第4條時讀數(shù)x2=________mm，相鄰兩條亮紋間的距離Δx=________mm。
③右下圖為小明根據(jù)實驗數(shù)據(jù)作出的I1-I2圖線（I1為電流表G的示數(shù)，I2為電流表A的示數(shù)），由該圖線可得：被測干電池的電動勢E=______V，內(nèi)阻r=______Ω。
22．（16分）如圖所示，質(zhì)量m=
23．（18分）如圖所示，光滑水平地面上停著一輛平板車，其質(zhì)量為
24．（20分）如圖所示，在以O(shè)為圓心，半徑為R=
17．如圖所示，置于水平地面上的盛水容器中，用固定于容器頂部的細(xì)線使一實心鋼球懸掛在水中,此時容器底對地的壓力為N1。由于某種原因細(xì)線突然斷裂，則鋼球在水中加速下沉的過程中，容器底對地面的壓力為N2，那么N1與N2相比較是
f t（v0+vm）
D.
―
mv20
19．如圖所示，P、Q是電量相等的兩個正電荷，它們的連線中點是O，A、B是PQ連線的中垂線上的兩點，OA＜OB，用EA、EB、UA、UB分別表示A、B兩點的場強(qiáng)和電勢，則
D. EA不一定大于EB， UA不一定大于UB
（2）若已知AB=l1，那么物塊第一次到達(dá)B點時的速度vB是多大？
24．（18分）空間某區(qū)域內(nèi)存在水平方向的勻強(qiáng)磁場B，在磁場區(qū)域內(nèi)有兩根相距l(xiāng)1的平行金屬導(dǎo)軌PQ、MN，固定在豎直平面內(nèi)，如圖所示。PM間連接有阻值為R的電阻；QN間連接著兩塊水平放置的平行金屬板a、b，兩板相距l(xiāng)2。一根電阻為r的細(xì)導(dǎo)體棒cd，導(dǎo)體棒與導(dǎo)軌接觸良好，不計導(dǎo)軌和導(dǎo)線的電阻。若導(dǎo)體棒cd以速率V向右勻速運動時，在平行金屬板a、b之間有一個帶電液滴恰好在豎直平面內(nèi)做勻速圓周運動。求：