选择题：114、无条件反射的反射弧是（）。A、由先天与后天共同形成的B、后天形成的 C、先天固有的

Administration of information and standardization are needed during the transfer

I don’t understand ____ believe him.( )(本题2.0分) A、 why don’t you B、 why you not

She is my best friend, so I know her very _____. ( )(本题2.0分) A、 good B、 fine C、

The collapse of the World Trade Centre has put U.S. economy in a difficult _____

求M0(3,1,-4)在平面∏：x+2y-z-1=0上的投影点.