In the new century, we still should _____ primary importance to the development of economy.
| A．perform | B．attack | C．seek | D．attach |
. One third of the area ______ covered with trees. About seventy percent of the trees ______ been planted recently.
| A．is; has | B．is; have | C．are; have | D．are; has |
Nowadays teens prefer going to the net-bar ______ they can chat with their friends by QQ or play computer games ______ some more reading.
| A．which; rather than do | B．where; to do |
| C．what; doing | D．where; to doing |
It has been announced that all the students ______ put on the masks before going to school in case they are infected with SARS virus.
| A．shall | B．will | C．need | D．may |
Some researchers are finding that daydreaming may be important to ______ mental health. Daydreaming, they say, is _____ good means of relaxation.
| A．the; / | B．/; the | C．/; / | D．/; a |
--- How long do you think it’ll be ______ I can go back to work?
--- Well, you’ll be feeling better by next weekend.
| A．before | B．when | C．until | D．than |