—A medical team was sent to Japan by air five hours ago.—So they ______________ have arrived by now. The flight usually takes four hours or so.

 He had no choice but to go on because it is their agreement that no one ______ quit the plan half way.

According to the school rules, no student _______ go out of school without the permission of the teachers.

Curious about the world around him, my son__   __ask me endless questions when he was young．

You had better _________ wine because you have to drive back home.