1、The children went home from the grammar school,their lessons______for the day.
A.finishing B.finished C.had finished D.were finished 此题答案选B,为什么不选C或D呢？
2、When I called you this morning,nobody answered the phone.Where_____?
A.did you go B.have you gone C.were you D.had you been 此题答案选C,为什么不选A呢？

1、The children went home from the grammar school,their lessons______for the day.
A.finishing B.finished C.had finished D.were finished
选B是因为它是一个独立主格结构用的非谓语动词。答案C不是被动，肯定不选。答案D只有在两个句子间有and /but/ or /so等连词连接构成并列句时才可使用。
2、When I called you this morning,nobody answered the phone.Where_____?
A.did you go B.have you gone C.were you D.had you been
这是一个习惯问题。中国人也许会问“你去哪了”，而此处问话人只想知道当自己打电话时，you不在家，在哪。