The biggest problem for most plants,which_______just get up and run away when threatened,is that animals like to eat them.

-- 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.

Please open the window, _____?

I wish that you ________ such a bad headache because I’m sure that you would have enjoyed the concert.

The manager proposed that Tom _________an opportunity to explain why he’d refused to go there.