If a person has not had enough sleep, his actions will ___him ____ during the day.
| A．give; in | B．give; away | C．give; out | D．give; up |
Most whales must come up for air after several minutes, _______ a few can stay under water for an hour or more.
| A．while | B．or | C．for | D．so |
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 |