问题

My mother was doing the cleaning in the sitting room ________ the telephone rang.
A:when
B:while
C:since
D:as soon as;
B:while
C:since
D:as soon as;
正确答案是:
同类题型
The ______ of new inventions(发明) should be to make life easier, not to make it more difficult.
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Why didn’t you go shopping with me two hours ago—Because my mother________ me outside.
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