All the donated money should be made full use _______the homeless people in Ya'an city of Sichuan province.

A．of helping

B．to help

C．of to help

D．to helping

水泵铭牌上标明的水泵允许吸上真空高度的数值一定是（）。

A.小于10m

B.大于10m

C.等于10m

D.小于5m