Tom was about to close the windows _____

试题详情及答案解析

Tom was about to close the windows ______ his attention was caught by a bird.

A．if

B．when

C．and

D．till

答案：B

试题分析：考查连词。本题考查固定结构be about to … when …正要做…..的时候，突然……。句意：汤姆正要关窗户的时候，突然他的注意力被一只小鸟所吸引了。故B正确。
考点：考查连词