沟通管理有哪四个过程？

Which of the following would be counted as frictional unemployment（）

A. Due to the negative growth of GDP, Smith was laid off.

B. Johnson was fired from his job after he got into an argument with his foreman.

C. Although there were jobs available, Jones was unable to find an employer with an opening.

腹胀逐渐加重，可考虑为高位肠梗阻。

所有金属材料在拉伸试验时都有屈服现象。

渐进式安全钳与瞬时动作式安全钳区别在于钳座是（），能使制动力限制在一定范围。

A.钢性结构

B.弹性结构

C.结构

D.固定结构

水轮发电机主轴的结构型式有（）。

A.一种；

B.二种；

C.三种；

D.四种;