（）和（）是喷油泵中最紧密的零件，它们经过精密选配互研而成，统称为柱塞偶件。

The nurse is caring for a client admitted to the hospital with a bowel obstruction. The nurse should wear sterile gloves when

A. inserting an indwelling urinary catheter.
B. giving a back rub on intact skin.
C. changing an oxygen system.
D. inserting an IV catheter.

He had ever climbed this mountain several months before, but _____ he couldn't find the way this time.

[      ]

A. anyhow

B. somehow

C. somewhat

D. sometime

既能泻下冷积，又能祛痰利咽治疗喉痹的药物是

A．大黄

B．芒硝

C．牛蒡子

D．巴豆

E．芫花

直线的正投影图是( )。

A．点

B．线

C．面

D．可能是点、可能是线

影响刀具工作角的因素有（）

A.进给运动

B.刀尖安装位置

C.刀杆安装倾斜度

D.主运动