问题补充:
This new kind of chemicals will help keep the air, soil and water from pollution.
A. free
B. empty
C. loose
D. short
答案:
(答案→)A. free
B. empty
C. loose
D. short
解析:考查形容词:A. free 自由的,免费的,free from免于,没有,B. empty 空的,C. loose松散的, D. short短的,句意:这种新的化学物质会有助于保持空气,泥土和水免于污染。选A。