认为社会分层是社会不平等的体现，是社会运行过程的需要，这是社会分层理论流派中的( )

A．进化论

B．冲突论

C．功能论

D．交换论

A vessel restricted by its ability to manoeuver by the nature of its work or its deep draft is（）.

A.hampered vessel

B.giving way vessel

C.vessel not under control

D.disabled vessel