下肢静脉显像最常用的显像剂是()
A.99Tcm-RBC
B.99Tcm-DTPA
C.99Tcm-植酸钠
D.99Tcm-MAA
E.99Tcm4O-
参考答案:D
—Where have you been?
—I got caught in the traffic jam; ______ I’m here just on time.
A.however
B.otherwise
C.though
D.anyhow
简述信息获取的一般过程。