新生儿先天不足的病因有（）

A.多胎

B.早产

C.孕妇体弱

D.胎盘、脐带异常

E.胎养、胎教不周

— You look upset. What’s the matter ?

— I had my proposal ______ again.

A．turned over

B．turned on

C．turned off

D．turned down