Mary didn’t understand made her deskmate so upset all the morning.
| A．it was that | B．why it was that |
| C．how that was | D．what it was that |
_______ , sound and video can now be stored on a PC, on the Internet, or using some form of portable storage. Which one of the following is not suitable?
| A．As digital technology developing |
| B．As digital technology develops |
| C．With digital technology developing |
| D．With the development of digital technology |
Not only________ vital for reducing fever and helping stop pain, but there are also other things that aspirin can help with.
| A． aspirin has proved | B．did aspirin prove |
| C．has aspirin proved | D．aspirin proved |
They kept trying, and their efforts finally _____. They got enough money to _____ their debt.
| A．are paid off; pay back | B．paid off; pay off |
| C．are paid for; pay back | D．paid back; pay off |
He is disappointed. He appears ____ what has happened to his competition.
| A．knowing | B．to know |
| C．having known | D．to have known |
I was watching the news on TV ________ the power went off.
| A．when | B．as | C．while | D．until |