自主高效練八年級英語外研版評議教輔
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20. I have made up my mind to take a break from social media.（改為同義句）
I have
decided to
take a break from social media.
答案：decided to
解析：“make up my mind”意為“下定決心”，其同義短語為“decide to”，原句時態為現在完成時，所以此處用“decided to”。
21. My grandparents have already been to Sanya.（改為否定句）
______
答案：My grandparents haven't been to Sanya yet.
解析：現在完成時的否定句是在助動詞“have/has”后加“not”，“already”在否定句中通常改為“yet”，放在句末。原句主語是“My grandparents”，助動詞用“have”，所以否定句為“My grandparents haven't been to Sanya yet.”。
22. People have improved air quality in the cities by driving less.（改為一般疑問句）
______
答案：Have people improved air quality in the cities by driving less?
解析：現在完成時的一般疑問句是將助動詞“have/has”提到主語之前，原句主語是“People”，助動詞用“have”，所以一般疑問句為“Have people improved air quality in the cities by driving less?”。
23. There will be life on that planet.（用現在完成時改寫句子）
______
答案：There has been life on that planet.
解析：現在完成時的結構為“have/has+過去分詞”，“there be”句型的現在完成時為“There have/has been...”，“life”是不可數名詞，所以用“has been”，改寫后的句子為“There has been life on that planet.”。
24. writer，David，a，has become，successful（.）（連詞成句）
______
答案：David has become a successful writer.
解析：根據所給單詞，“David”是主語，“has become”是謂語，“a successful writer”是賓語，所以連成的句子為“David has become a successful writer.”。
