We’ve failed three times in the experiment,so we’ll have to do it       time.

We can't use it to tie the goods because it ________ be broken at the weakest position.

 If you leave the club, you will not be ________back in.

Some blood types are quite common, others are regionally        , and still others are rare everywhere.

 The newcomer is quite ________ to office work.Why not offer her some practical tips?