We live in a society _______ there is a great deal of debate about competition.

A．which

B．where

C．when

D．that

对有毒固体废物的堆放，必须采取()防止危害的措施，并设置有害废物的标志。

A.防水 

B.防渗 

C.防流失 

D.防盗窃 

E.防热辐射