I’m sure that if you make good use of your time your English will be improved in a short

问题补充：

I’m sure that if you make good use of your time, your English will be improved in a short time.

A. extra

B. common

C. special

D. spare

答案：

A. extra

B. common

C. special

(答案→)D. spare

解析：词义辨析。 A. 额外的 B. 普通的 C. 特别的 D. 多余的。句意：我相信如果你如果能好好利用你的空闲时间，你的英语会在短时间内提高。故选D。