两顶尖支承工件车削外圆时，刀尖在垂直方向上的移动轨迹与工件回转轴线间产生______误差，影响工件素线的直线度。

A．直线度

B．平行度

C．等高度

A certified nursing assistant (CNA) is caring for a client with Clostridium difficile diarrhea and asks the charge nurse, "How can I keep from catching this from the client" The nurse reminds the CNA to wash her hands and to ensure the client is placed

A. on protective isolation.
B. on neutropenic precautions.
C. in a negative-pressure room.
D. on contact isolation.