Question

We were about to go out for a walk ______ it began to rain.

A．while

B．before

C．a(chǎn)s

D．when

Answer 1

D

試題分析：考查固定句式。固定句式：be about to do sth when…正要做某事在這時…。本題中的when是一個并列連詞，意為：在那時；故D正確。
點評：固定句式：be about to do sth when…正要做某事在這時…。本題中的when是一個并列連詞，意為：在那時；對于這樣的固定句式，平時要加強識記。