间接ELISA的标记物为 （）
A.酶标抗原
B.酶标第一抗体
C.酶标第二抗体
D.酶标亲和素
E.酶标生物素
参考答案：C
--- Who are you waiting for?
--- ______ us a lecture this afternoon.
A． The professor wants to give
B． The professor will give.
C． The professor about to give
D． The professor to give.
硬膜外腔注射吗啡不产生血压下降。
