Dr. Smith, as well as his wife and daughters , ______ visit Beijing this summer. 

A  is going to    B are going to     C was going to     D  were going to

脐静脉插管后导管末端应位于（）。

A.上腔静脉

B.脐静脉

C.下腔静腔

D.肝静脉

E.颈静脉