有中枢抑制作用的成分是（） A.和厚朴酚 B.木兰箭毒碱 C.黄酮 D.厚朴多糖 E

They _____ on the program for almost one week before I joined them, and now, we ____on it as no good results have come out so far.

A．had been working; are still working

B．had worked; were still working

C．have been working; have worked

D．have worked; are still working

哪种利尿药不宜与氨基糖苷类抗生素合用（）。

A.氨苯蝶啶

B.螺内酯

C.呋塞米

D.氢氯噻嗪

E.环戊噻嗪

简述兔的胃内注射法。

节温器失灵将造成冷却系温度（）。

A、过高

B、过低

C、都错