为了群呼号在300~399之间的公务号码，需拨（）。

—Could you tell me _______? I must find him.

—Sorry. I don't know. But he was here just now. [ ]

A. where Tom was

B. where has Tom gone

C. where Tom is

D. where can I find Tom

粉末中可见草酸钙簇晶排列成行的药材为

A．黄柏
B．厚朴
C．杜仲
D．肉桂
E．牡丹皮

肺血栓栓塞症患者，用于经静脉导管碎解和抽吸血栓的适应证有（）

A.肺动脉主干或主要分支大面积肺血栓栓塞症

B.不能行溶栓和禁忌抗凝治疗

C.经溶栓或积极的内科治疗无效者

D.以上都是

钢筋料头如何处理才是最佳做法？

为什么酶制剂的生产主要以微生物为材料？