以下9－13题为套题企业年金在国外已经有一百多年的历史，随着养老保险制度的发展，企业

手工电弧焊时，冷却速度增加，焊缝的硬度（）。

A、增加

B、不变

C、减小

D、稍微减小

My father is now in his late forty but he looks young for his age. He is very strict with me, especial in my studies. Besides, I know he loves me deeply in his heart. Once I had failed to do well in my math exam, I was afraid that it would make my father angry and disappointing. On contrary, he said I had tried my best and offered him a few words of encouragement. He told me that there is no need to feel bad about one and two failures and the most important thing is to learn anything from failure and never give up. Today is Father’s Day and I want to say thank you for my father.

某气体可能由初中化学常见的一种或多种气体组成，已测定其中只含有碳、氧两种元素，且质量比为1：2，则关于该气体的说法正确的是（　　）

A．一定是纯净物

B．一定含CO

C．最多可能的组合有2种

D．可能是O₂、CO₂的混合物

XJ450修井机前部车轮前束为（）mm。

A、0~1

B、0~2

C、0~3

D、0~4

下列各项属于生产运作系统的软件部分的是（）

A.生产计划

B.生产技术

C.生产设施

D.生产能力