______on the MSN ,some people often use "88" for "good-bye "A.When chat B.When chatting C.When chatted D.When to chat
问题描述：
______on the MSN ,some people often use "88" for "good-bye "
A.When chat B.When chatting C.When chatted D.When to chat
答
B when doing 当做.事情时 如when doing the exam,we should be careful.实际上这里完整一点的说是这样when （we are） doing the exam,we should be careful.而when to do何时做.如she will tell you when to do it...