I don’t doubt _____ he is a brilliant scientist, but can he teach?
| A．whether | B．if | C．that | D．what |
________ all of them are strong candidates, only one will be chosen for the post.
| A．Since | B．While |
| C．If | D．As |
Nowadays people are more concerned about the environment __________ they live.
| A．what | B．which |
| C．when | D．where |
Tony lent me the money，__________ that I'd do as much for him.
| A．hoping | B．to hope |
| C．hoped | D．having hoped |
When the building was completed, he paid __________ the workers.
| A．off | B．for |
| C．back | D．in |
—I love the Internet. I've come to know many friends on the Internet.
—__________. Few of them would become your real friends.
| A．That's for sure |
| B．It's not the case |
| C．I couldn't agree more |
| D．I'm pleased to know that |