构成人体的本原物质是
A．天地之精气
B．元气、宗气、营气、卫气
C．水谷之精气
D．天气
E．地气
参考答案：A
由证券A和B形成的证券组合C的收益率总是介于证券A和证券B的收益率之间。( )
________________ to improve our English?
A．What do you think we should do
B．Do you think what do we should
C．What do you think should we do
D．Do you think what should we do
