I'm sure that middle school students will benefit ________ taking exercise every day, which is

________ great benefit ________ their health. [ ]

A . by; of; at  

B. from; of; to

C. of; by; to  

D. by; from; at

项目业主为了降低项目风险和融资成本，往往需要( )。

A．银行参股

B．律师事务所提供服务

C．会计师事务所提供咨询服务

D．工程咨询单位提供咨询服务