Tom was about to close the window () his attention was caught by a bird 为什and不可以

题目

Tom was about to close the window () his attention was caught by a bird 为什and不可以
and可以表并列啊 为什么不可以？ 这个题选项 Awhen B if C and D till 答案是A 还有 有没有 be about to do ...when的结构？谢谢:-)

答案

填when.
这个句子前后不是递进关系,不能填and.
有的,这里正是be about to do sth when.结构,“正想做某事这时（突然）.”的意思.句子的意思是,“Tom正要关窗,这时（忽然）一只鸟吸引了他的注意力.”