A well-written composition__________ a good choice of words and clear organization among other things.
| A．calls on | B．calls for | C．calls up | D．calls off |
Some researchers believed that there is no doubta cure for AIDS will be found.
| A．which | B．that | C．what | D．whether |
You’d better _____ some money for special use.
| A．pick up | B．set aside | C．put off | D．give away |
Many studentspreparing for the midterm examination.
| A．are engaging in | B．are engaging themselves |
| C．are engaging themselves | D．are engaged in |
________ from space, the earth , with water_______ seventy percent of the surface , looks like a blue ball.
| A．Seen ; covered | B．Seen ; covering |
| C．seeing ; covering | D．Seeing ; covering |
— What made her so sad？
— _____ she failed in the examination.
| A．That | B．Because | C．As | D．Since |