病儿素喜出汗，以头部、肩背明显，动则益甚，神倦乏力，易于感冒，脉弱。其治法应为（）

A.调和营卫

B.益气固表

C.益气养阴

D.滋阴补肾

E.补益肺脾

In order to make students have a good knowledge of science subjects, they are encouraged to______ their own science experiments.

A．operate

B．direct

C．manage

D．conduct