当力的作用线通过矩心时,力矩()A.等于零 B.等于力的大小 C.等于无穷大 D.等

题型:单项选择题

问题:

当力的作用线通过矩心时,力矩()

A.等于零

B.等于力的大小

C.等于无穷大

D.等于某非零的有限值

考点:轮机工程静电力的基本概念静电力的基本概念题库
题型:单项选择题

无症状性心肌缺血的防治中不包括()

A.预防感染治疗

B.β受体阻滞剂治疗

C.硝酸酯类药治疗

D.适当减轻工作

E.钙通道阻滞剂治疗

题型:单项选择题

阅读理解。

     "Get out of the plane!" Justin shouted.Teddy and he dropped to the ground,...

      When Kathy and Victor reached the edge of the meadow (牧场)flames of the fire were shooting

more than five meters into the air.

      Kathy couldn't believe what she was seeing.One glance told her they needed medical attention

immediately.She questioned Victor, "Are you able to find someone nearby for help?"

      "There are no farmers, nor villagers nearby," he replied.

      "I'm a distance runner, and I'll go for help." Looking at the seriously injured men, Kathy said to

Victor, "It may take me several hours to get out." She started out.

      When she was 23, Kathy set a women's record in a Marathon of 42 kilometers.But now she

was running the race of life.She had nearly 30 kilometers of hard wilderness to cover to get help.

      Kathy had been running for two hours.This was far back into the wilderness.The country path

was growing vague (模糊).She stopped to take a quick compass (指南针) reading.Yes, she had

run almost for more than 20 kilometers.Her heart fell, her muscle aching.And finally she saw her car

in the distance.

      She jumped into the car and sped away.She reached a holiday house and called the police.

      During the wait, she walked around, relaxing her legs and drinking water.It took almost two hours

for a police helicopter to reach her at the trail (小路) end.They needed her for one more task.

1.Who actually had the airplane accident?

A.Justin himself                  

B.Kathy and Victor

C.Justin and Teddy                

D.Kathy herself

2.The underlined part "Now, she was running the race of life" means that ____.

A.Kathy would set up a new record

B.Kathy was running for the lives of others

C.Kathy would run a race alone

D.Kathy couldn't rely on Victor this time

3.Kathy stopped to have a look at her compass because ____.

A.the country path was getting vague    

B.she had completely lost her way

C.she wasn't sure of her own memory  

D.there was only the wilderness

4.What do you think Kathy's final task would be?

A.Giving the injured food and drinks.  

B.Taking the injured to the hospital.

C.Going back to put out the big fire.    

D.Showing the police the crash site.

题型:单项选择题

我们的民族关系是完全新型的社会主义民族关系。社会主义民族关系的主线是

A.平等

B.团结

C.互助

D.和谐

题型:单项选择题

关于细菌性痢疾所累积结肠部位的病理改变哪项正确()

A.弥漫性伪膜形成

B.肠壁肌层溃疡

C.极易穿孔

D.黏膜固有层炎症和溃疡

E.中毒性痢疾黏膜病变重

题型:单项选择题

建设投资项目的可行性研究,其内容一般包括______等。

A.项目建设的必要性

B.投资估算

C.市场分析

D.建设方案

E.确定性分析

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