—People often don't appreciate what they have, do they?
—No, _________ they lose it.
| A．if | B．after | C．until | D．when |
The teacher has confidence in the naughty but clever boy and is sure that he _____ to a key university．
| A．would be admitted | B．was admitted |
| C．has admitted | D．will be admitted |
I wish my house would be built _____we can enjoy beautiful scenery with mountains and rivers．
| A．in which | B．what | C．where | D．that |
What seems to be a simple idea always turns out _____ that is hard to put into practice．
| A．the one | B．one | C．ones | D．another |
We regret _____ you that．because of the necessary repair, our library will be closed next month．
| A．to inform | B．informing | C．to inform of | D．of informing |
To my great joy．I got a chance to take a photo with Andy after the vocal concert, which I _____forward to for years．
| A．have been looking | B．had been looking |
| C．looked | D．had looked |