单项选择题
This machine （）out of order very often, but now it works well.
A.is used to be B.was used to be C.used to be D.was used to
单项选择题 When we arrived here yesterday, their ship （）for three days.
单项选择题 The accident resulted （） the motorman’s carelessness.
单项选择题 The second engineer seemed to know what the sign （）.
