Although they plant trees in this area every year, the tops of hills are still ______.

A .blank         B. hollow           C. vacant           D. bare

Although they plant trees in this area every year, the tops of hills are still ______.

They plant trees in order to avoid the soil _______ away from the hill.

A. washing       B. washed     C. being washing     D. being washed

（2010·黑龙江大庆实验中学高三第二次月考）      28.They plant trees in order to avoid the soil _______ away from the hill.

A. washing       B. washed     C. being washing     D. being washed