![](https://cos-cdn.shuashuati.com/pipixue-wap/2020-1230-1107-56/ti_inject-812ce.png)
Forests of pine and fie cover two thirds of this area.
A.
Forests of pine and fir is covered two thirds of this area.
B.
Two thirds of this area are covered by forests of pine and fir.
C.
Two thirds of this area is covered by forests of pine and fir.
D.
This area is covered two thirds of forests of pine and fir.