The field research will take Joan and Paul about five months; it will be a long time _____ we meet them again.
| A．after | B．before |
| C．since | D．when |
You shouldn't leave the water ________ while you wash clothes; it's a waste of water．
| A．run | B．running | C．being run | D．to run |
There is no experience you can have ________ is more exciting than skating on real ice．
| A．that | B．it | C．what | D．this |
I hear you are saying that doctors should be highly paid, and this is ________ I disagree．
| A．why | B．where | C．what | D．how |
—I'll tell something about the change in your job tomorrow．
—You ________ me some time earlier．
| A．ought to tell | B．would have told | C．must tell | D．should have told |
A student _________ his family lots of money for education．
| A．spends | B．costs | C．takes | D．pays |