识别频率的容限为（）。 A.1020Hz±5Hz B.1020Hz±10Hz C.1

介词填空。

1. They are used _____ seeing in the dark.

2. They were invented _____ 1863.

3. George wanted _____ make the customer happy.

4. Potato chips were invented _____ a chef called George Crum.

5. He was boiling drinking water _____ an open fire.

6. Some leaves _____ a nearby bush fell _____ the water and remained there for some time.

7. This beverage was discovered _____ three thousand years before that.

完全性右束支传导阻滞的心电图诊断包括（）

A.室上性起搏点

B.QRS>0.12s

C.Vl、V2导联的图形为rSR，型，

D.QRS<0.12s

E.Vl、V2呈RS图型

治疗高血压病的p阻滞剂药物及剂量是下列哪几项（）

A.阿替洛尔（氨酰心安）6.25～25mg，2次／日

B.美托洛尔（倍他洛克）25～50mg，3次／日

C.普洛耐尔（心得安）10～20mg，3次／日

D.地尔硫（合心爽）30～60mg，3次／日

E.硝苯地平（心痛定）10mg，3次／日

天然气

房水循环途径