________you’ve experienced it，you can’t understand how I felt.
| A．Once | B．Because |
| C．Unless | D．While |
It is generally believed that constant reading and comprehending can __________ our mental ability of comprehension while physical exercise can help build up our body.
| A．stress | B．effect |
| C．strengthen | D．decide |
__________ in a university in the U. S. A.，Chinese students must have excellent speaking and writing abilities in English.
A. EducateB. Being educated
C. To be educatedD. Having educated
I don't know whether the books __________ to the homeless children next month are really useful.
| A．given | B．to be given |
| C．giving | D．which were given |
There was no more than one iPhone 4S in the store, so I had no choice but __________.
| A．take | B．taking |
| C．taken | D．to take |
The machine has been made easier for it __________.
| A．to operate | B．operated |
| C．being operated | D．to be operated |