Question

【题目】Tom was about to close the window　　　　his attention was caught by a bird.

A. when B. if

C. and D. till

Answer 1

【答案】A

【解析】

句意：汤姆正要关上窗户，就在这时一只鸟引起了他的注意。在句式“...be about to do...when...”中，when作并列连词，相当于and at that time，句中was about to close为标志词，故答案为A项。