We must do something to stop people from ______.

A．to throw litter about

B．to throw litter into

C．throwing litter about

D．throwing litter into

属于白内障的改变的有（）

A.正常晶状体有不同程度的轻度混浊

B.晶状体核硬化

C.晶状体光学密度增加

D.晶状体灰白色混浊

E.晶状体皮质纤维淡淡的放射状纹理