There are so many kinds of mobile phones here. We can’t decide _____.

I had to buy ofthese books because I didn’t know which one was the best.

The scientist’s last words _________us thatwe should protect the environment around us.

I thought you wouldn’t mind.—Well, as a matter of fact I ____; but you should have asked me first.

I have got used to staying up late at night I’m really tired and want to go to sleep early[ ]