The government has taken some measures to prevent more trees from _______.   [ ]

A. being cut down

B. cut down.    

C. cutting down    

D. been cut down

牙列缺失导致的软组织改变中不正确的一项是（）

A.肌肉更具有弹性

B.黏膜变平

C.肌肉张力平衡破坏

D.敏感性增强

E.软组织萎缩