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

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When we arrived here yesterday, their ship （）for three ...

单项选择题When we arrived here yesterday, their ship （）for three days.

A.has left
B.had left
C.has been away
D.had been away

The accident resulted （） the motorman’s carelessness.A....

单项选择题The accident resulted （） the motorman’s carelessness.

A.in
B.to
C.from
D.by

The second engineer seemed to know what the sign （）.A.s...

单项选择题The second engineer seemed to know what the sign （）.

A.stand by
B.stand for
C.stood by
D.stood for

船舶电气与船舶安全