Sometimes we need true friends’ shoulders ____we can cry to free ourselves from pain.
| A．by which | B．on which |
| C．in which | D．with which |
Your composition is written very well ______________ some spelling mistakes.
| A．except for | B．except that | C．besides | D．except |
________ makes mistakes must correct them.
| A．Who | B．That | C．Whoever | D．Whatever |
We must take steps to prevent the __________ world population.
| A．exploded | B．exploding | C．explosion | D．explosively |
The amount of money that he saved reached _________ 30000 dollars.
| A．as many as | B．as much as | C．as high as | D．as far as |
It is pretty well understood_______controls the flow of carbon dioxide in and out of the atmosphere today．
| A．that | B．when | C．what | D．which |