31．Those who bring sunshine into the lives of others cannot keep ____ from themselves．
| A．it | B．one | C．those | D．Them |
Scientists study ________ human brains work to make computers. (2012·四川，17)
| A．when | B．how |
| C．that | D．whether |
It suddenly occurred to him________he had left his keys in the office. (2012·江西，25)
| A．whether | B．where |
| C．which | D．that |
Jerry did not regret giving the comment but felt ________ he could have expressed it differently. (2012·北京，24)
| A．why | B．how |
| C．that | D．whether |
As many as five courses are provided，and you are free to choose ________ suits you best. (2012·陕西，20)
| A．whatever | B．whichever |
| C．whenever | D．wherever |
It doesn’t matter________you turn right or left at the crossing—both roads lead to the park. (2012·天津，9)
| A．whether | B．how |
| C．if | D．when |