目标市场对产品毫无兴趣或漠不关心，这种状态的需求称为（）

A．不规则需求 

B．潜伏需求 

C．无需求 

D．负需求

There are many things in different areas ________ we can do to reduce the possible dangers of AIDS.

A．that

B．there

C．what

D．where