匀质粘性土土坡失稳破坏时,其滑动面通常是()形。

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问题:

匀质粘性土土坡失稳破坏时,其滑动面通常是()形。

考点:地基处理及桩基技术继续教育地基处理及桩基技术继续教育题库
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如图所示,平行板电容器板长为L,极板间距为2L,上板带正电,忽略极板外的电场. O、O′是电容器的左右两侧边界上的点,两点连线平行于极板,且到上极板的距离为L/2. 在电容器右侧存在一个等腰直角三角形区域ABC,∠C=90°,底边BC与电容器的下极板共线,B点与下极板右边缘重合,顶点A与上极板等高. 在电容器和三角形区域内宥垂直纸面向里的匀强磁场,磁感应强度大小分别为B1=B、B2=2B.一带正电的粒子以初速度v0从O点沿着00′方向射入电容器,粒子的重力和空气阻力均不计.

(1)若粒子沿 00′做直线运动,进人三角形区域后,恰从顶点 A飞出,求两极板间的电压U和带电粒子的比荷

q
m

(2)若撤去电容器中磁场的同时,把三角形区域内的磁场方向变为垂直于纸面向外,但磁感应强度大小不变.此后,同一带电粒子仍以相同的初速度v0 从0点沿着 00′方向射入电容器,求粒子从三角形区域飞出时距离飞出边某一顶点的距离.

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患儿,男,出生后表现持续性鹅口疮,9个月后因真菌性肺炎死亡。尸检发现其胸腺发育不全。此患儿发生持续感染主要由于()。

A.继发性免疫缺陷 

B.细胞免疫缺陷 

C.体液免疫缺陷 

D.吞噬细胞缺陷 

E.补体系统缺陷

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阅读理解

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     Today I am going to ask you to support Wikipedia with a donation.

     Wikipedia is built differently from almost every other top 50 website.We have a small number of paid

staff, just twentythree.Wikipedia content is free to use by anyone for any purpose.Our annual expenses are less than six million dollars.Wikipedia is run by the nonprofit Wikimedia Foundation, which I founded in

2003.

     Wikipedia is driven by a global community of more than 150,000 volunteers-all devoted to sharing

knowledge freely.Over almost eight years, these volunteers  have  contributed  more  than 11 million articles in 265 languages.More than 275 million people come to our website every month to access information,

free of charge and free of advertising.

     But Wikipedia is more than a website.We share a common cause:Imagine a world in which every single person on the planet is given free access to the sum of all human knowledge.That's our commitment.

     Your donation helps us in several ways.Most importantly, you will help us cover the increasing cost of managing global traffic to one of the most popular websites on the Internet.Funds also help us improve the software that runs Wikipedia-making it easier to search, easier to read, and easier to write for.We are

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keep it free and strong, but we need the support of thousands of people like you.

                                                                                                                                       Thank you,

                                                                                                                                       Jimmy Wales

1. What do the second and third paragraphs mainly talk about?

A. Why you should donate to Wikipedia.

B. How much the workers are paid.

C. How Wikipedia is run.

D. How many people contribute to Wikipedia.

2. All the following are the reasons for the need of your donation EXCEPT________.

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B. to update the software that runs Wikipedia

C. to raise the salaries of the staff

D. to pay the cost of running the website

3. What does the underlined word "That" in Paragraph 4 refer to?

A. Free access to all human knowledge.

B. Human knowledge.

C. Every single person.

D. A common cause.

4. Which of the following is TRUE about Wikipedia?

A. It only has 23 workers at present.

B. It will run a national park or a school.

C. It has got much help from other people.

D. It may put some advertisements to earn money.

5. What's the author's purpose of writing this text?

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如果离心泵发生气蚀现象,现场应()。

A.应停泵检查

B.排水

C.视情况处理入口过滤网或入口压力低的问题

D.继续运行

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关于病理性缩复环,下列哪项是错误的()

A.是子宫破裂先兆

B.由于分娩受阻所致

C.环的下方有压痛

D.腹部脐水平可见一环状凹陷

E.环的位置不随宫缩而上升

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