—Doyouknow______?—Yes.SheisdoingherhomeworkA.whatisyoursisterdoingB.wha

—Do you know ______?—Yes. She is doing her homeworkA.what is your sister doingB.what your sister is doingC.when your sister is doing homeworkD.where is your sister doing homework

B解析考查点：考查宾语从句以及句意。解题思路：宾语从句用陈述句语序，根据答句：是的，她正在做作业，可知问句句意：你知道你的姐姐正在干什么吗？故选B。

正好我需要