问题
选择题
Do you know _______ in Japan?
A． when nuclear(核) accidents happened
B． when did nuclear accidents happen
C． when nuclear accidents happen
D． when do nuclear accidents happen
答案
答案：A
此题重点考查宾语从句的时态和语序问题；不管哪种句式充当宾语从句都要用陈述句语序，因日本的核泄漏事件发生在过去，故用过去时。
