What _______ pity that you must leave now! It is such _______ great fun to have dinner with you．
| A．a; a | B．a; the | C．/; a | D．a; / |
I think humour is a vital form of entertainment, ____ it makes us laugh and laughing keeps us healthy.
| A．when | B．after | C．if | D．because |
The UN is an important international organization _____helps many people around the world.
| A．who | B．that | C．where | D．/ |
When you get on stage for the first time, you may be surprised by ______bright the lights are.
| A．what | B．so | C．how | D．too |
If you had joined the chat room ten minutes ago, you ______what we were talking about!
| A．have known | B．knew | C．would have known | D．would know |
Yesterday, when I went to his office, he ______ online for some information. I think it will be an interesting lecture.
| A．searched | B．was searching | C．would search | D．has searched |