省略

Look out for cars, when ________(cross)the street．

省略

Don’t come in unless ________(invite)to．

省略

He is very famous here, so we had no trouble ________(find)him yesterday．

省略

I’m very busy preparing for the exam, so I can’t help ________(do)the house work．

省略

What doctors can do is ________(save)people’s life．