---Tell me what happened ______ you?---When the thief broke in, I happened ______ in the sitting．A.to;to readB.to;to be readingC.about;to readD.about;to be reading
网友回答
B解析某人发生什么事了应用句型sth．happens to sb．；第二空是过去某一点时间(When the thief broke in)发生的事，故用过去进行时，即happened to be doing sth．。