I see four kinds of pressure working on college students today: economic pressure, parental pressure, peer pressure, but self-induced pressure.

A．and

B．or

C．nil

D．with

Ccr为下列哪项时表明需进行透析治疗（）。

A.51～70ml／min

B.31～50ml／min

C.<30ml／min

D.<20ml／min

E.<10／min