Tom was doing his homework——his mother was cooking选填when或者while,并说明理由

分类: 作业答案 • 2022-04-14 23:34:12

问题描述：

Tom was doing his homework——his mother was cooking
选填when或者while,并说明理由

答

while 因为when后面接一般过去时,也就是动词过去式,而while后接的是进行时,也就是be动词+动词ing形式