He _______ the best person you had been expecting for the job, but who else _______?
| A．may not be; could be |
| B．couldn’t be; might be |
| C．might not have been; could have been |
| D．mustn’t be; must have been |
The numbers that researchers get from the experiments can be _______, just like number puzzles.
| A．disappointing | B．inspiring | C．worrying | D．confusing |
_______ the house is empty, memories flood my mind of a time when it was filled with life.
| A．Since | B．Unless | C．As if | D．Even though |
By the time a child is five, he _______ hundreds of hours of television.
| A．will watch | B．will have watched | C．had watched | D．is watching |
There is nothing wrong with using a credit card for purchases. It’s more _______ than carrying loads of cash.
| A．convenient | B．valuable | C．sensitive | D．innocent |
An earthquake of 9 magnitude struck off the coast of Japan on Friday,______ thousands of people dead and more missing．
| A．caused | B．causing | C．having caused | D．to cause |