The doctor thought ___ would be good for you to have a holiday.

–Do you think they have as many books as they’ve described? --Well, in my opinion, they have few books, if ______.

There is            wrong with this computer. It doesn’t work well.

Your shoes are old. Why not buy a new _______?

Larry asks Bill and Peter to go on a picnic with him, but ______ of them wants to, because they have work to do.