____of the land in that district____ covered with trees and grass.

A．Two fifths；is

B．Two fifth；are

C．Two fifth；is

D．Two fifths；are

节肢动物中永久性体表寄生虫是（）

A.恙螨

B.虱

C.臭虫

D.硬蜱

E.软蜱