In most western countries, on April Fool’s Day, people often play trick on each other; children especially have great fun.
| A．a; a | B．the; the | C．a; / | D．/; a |
Marie witnessed everything but it is amazing that she______ have said nothing about the murder.
| A．should | B．may | C．must | D．can |
I am looking forward to the time ______ I can work as a volunteer for the Youth Olympics .
| A．what | B．when | C．which | D．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 |