左肾静脉正确的走行位置是位于（）。

A.腹主动脉后方

B.肠系膜上动脉前方

C.脾静脉的前方

D.腹主动脉与肠系膜上动脉之间

E.腹主动脉与肠系膜下静脉之间

A series of debates between the major candidates ________ scheduled last week.[      ]

A. is  

B. are

C. was  

D. were