With more forests being destroyed, huge quantities of good earth      each year. [ ]

A. is washing away    

B. is being washed away

C. are washing away  

D. are being washed away

由于空间距离和视觉生理的限制，眼睛辨别不出过小或过远物体的细节，把各不相同的色块感受成一种新的色彩，这种现象称为（）

A.模糊混合

B.平均混合

C.空间混合

D.错位混合