--- Has Li Lei finished his work today?
--- I have no idea, but he ______ it when I saw him this morning.
| A．had done | B．would do | C．was doing | D．did |
Don’t promise anything ______ you are one hundred percent sure.
| A．whether | B．after | C．how | D．unless |
We’ll have a picnic in the park this Sunday _________ it rains or it’s very cold.
| A．since | B．if | C．unless | D．until |
There were some chairs left over _____ everyone had sat down.
| A．when | B．until | C．that | D．where |
For many cities in the world, there is no room to spread out further, _______ New York is an example.
| A．for which | B．in which | C．of which | D．from which |
I haven’t seen Ann for ____ long that I’ve forgotten what she looks like.
| A．such | B．very | C．so | D．too |