气割时，由于局部的（）作用，使钢板和割件发生变形，影响割件的_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

气割时，由于局部的（）作用，使钢板和割件发生变形，影响割件的精度。

A、切割

B、加热

C、断裂

D、不确定

答案

参考答案：B

完形填空

A little boy invited his mother to attend his school’s first teacher-parent meeting. To the little boy’s ___1___, she said she would go. This ___2___ be the first time that his classmates and t eacher ___3___ his mother and he felt ___4___ of her appearance. Although she was a beautiful woman, there was a severe scar(疤痕) that ___5___ nearly the entire right side of her face. The boy never wanted to ___6___ why or how she got the scar.
At the meeting, the people were ___7___ by the kindness and natural beauty of his mother ___8___ the scar, but the little boy was still embarrassed and ___9___ himself from everyone. He did, however, get within ___10___ of a conversation between his mother and his teacher.
The teacher asked ___11___, “How did you get the scar on your face?”
The mother replied, “___12___ my son was a baby, he was in a room that caught fire. Everyone was ___13___ afraid to go in because the fire was ___14___, so I went in. As I was running toward his bed, I saw a long piece of wood coming down and I placed myself over him trying to protect him. I was knocked ___15___ but fortunately, a fireman came in and saved both of us.” She ___16___ the burned side of her face. “This scar will be ___17___, but to this day, I have never ___18___ what I did.”
At this point, the little boy came out running toward his mother with tears in his eyes. He held her in his arms and felt a great ___19___ of the sacrifice(牺牲) that his mother had made for him. He held her hand ___20___ for the rest of the day.

B．disappointment

B．think about

A．in sight of

B．by means of

D．in spite of

A．understanding

A．out of control

B．under control

D．over control

D．frightening

问答题简答题

PLC控制系统的运行方式有几种？