.She had just finished her homework _________her mother asked her to practice playing the piano yesterday.
问题描述：
.She had just finished her homework _________her mother asked her to practice playing the piano yesterday.
A.when B.while C.after D.since
感觉AB都可以,
答
答案只可以是A,因为while后面应跟着一个持续的动作,多以进行式时态语标示.不要被playing一字混淆了,asked才是此谓句的动词.