Question

Mr Green didn’t know ______ last night.

A．when does his son come back	B．when his son comes back
C．when his son come home	D．when his son came home

Answer 1

D

動(dòng)詞know后跟的是一個(gè)賓語從句，要用陳述句的順序，故A不正確，主句是過去
時(shí)，從句要用過去時(shí)一種，只有D用的是過去時(shí)，故選D。