This new kind of chemicals will help keep the air soil and water from pollution.A. freeB.

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。