With trees and grass39.6% of the urban area the city has taken on a new look.A. coveringB.

问题补充：

With trees and grass39.6% of the urban area，the city has taken on a new look.

A. covering

B. covered

C. to be covered

D. being covered

答案：

(答案→)A. covering

B. covered

C. to be covered

D. being covered

解析：动名词做定语表示正在发生的，伴随的状况，过去分词表示发生过的事情，不定式表示将要发生的事情，这里树木和草地是cover的动作实施者，不用被动语态，故选A。随着树木花草覆盖了城市39.6%的地区……