我飄过
幼苗
共回答了11个问题采纳率:90.9% 举报
选C.
what you are supposed to do是主语从句,而且引导词在从句中作宾语,that和when都不可以,所以A、B排除.
is后面是表语,应该用to change不定式的,这里to省略了.具体用法是:
当主语部分有动词do的某种形式时,用作表语的不定式可以省略to.如:
What you first do is (to) mix the egg with flour.你先得把鸡蛋和面粉和好.
All I did was (to) touch the window,and it broke.我只不过碰了一下窗户,玻璃就碎了.
1年前
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