第二部分英语知识运用（共两节，满分45分）
第一节：单项填空（共15小题，每小题1分；共15分）
从A、B、C、D四个选项中选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
21.This bag is twice ______ weight of that one. You’d better carry ______ lighter one of the two.
A. /; / B. a; the C. the; the D. the; a
As your instructor(教师) advised, you ought to spend your time on something ____ researching into.
| A．precious | B．worth | C．worthy | D．valuable |
_____ the fact that his initial(开始的)experiments had failed, Pro. White persisted (坚持) in his research.
| A．Because of | B．As to | C．In spite of | D．In views of |
—Do you have enough to ________ the cost of your board at school?
—Oh yes, enough and to spare.
| A．cover | B．spend | C．fill | D．spare |
When I talked with my grandma on the phone, she sounded weak, but by the time we ___ up, her voice had been full of life.
| A．were hanging | B．had hung | C．hung | D．would hang |
Gun control is a subjectAmericans have argued for a long time .
| A．of which | B．with which | C．about which | D．into which |