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粘着作用

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参考答案：

滚动摩擦时，摩擦副之间也会产生粘着，但滚动摩擦产生的粘着接点在分离时，其方向是垂直于界面的，因此没有接点的增大现象。而滑动摩擦时所产生的接点在分离时，其方向与界面相切，因此有接点的增大现象。这是滚动摩擦系数小于滑动摩擦的原因之一。一般说来，滚动摩擦的粘附分量可能只占摩擦阻力中的一部分。但对于特定情况下的金属滚动，如硬球在不同的金属薄层上滚动时，粘附分量仍然是不同金属副滚动摩擦系数的主要部分

多项选择题

下面各项哪些项与外因性不均称型胎儿宫内发育迟缓无关（）

A.属继发性生长发育不良

B.孕早期胚胎发育正常，正常至孕晚期才受到有害因素的影响

C.由遗传因素引起

D.有害因素的影响

E.一些合并症致使胎盘功能不全
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阅读理解
第一节：（共15小题，每小题2分，满分30分）
A                                                                             

Joshua, Helmut, and Bethlehem 
Michelle O. Donovan
ISBN 9781462058679
Life is not easy for nine-year-old Joshua during World War II. 
Because of his family’s Jewish background, they are sent to live in the concentration camps (集中营). Scared and alone, Joshua one day makes frinds with a little mouse he calls Bethlehem who becomes his closest friend.

Encourage Me!
Inspirational Poetry
Gloria Coykendall
ISBN 9781412027854
It is an easy to read collection of poems originally written to encourage in faith and to be a cure for chromic depression(长期抑郁) … cure to strengthen identity and purpose.

More Things in Heaven
Bill Bosworth
ISBN 9780595433582
In his More Things in Heaven, Bill Bosworth presents presents the highlights of his 83 years of life, including his trips to India and the study of the writings of several great spiritual leaders.
More things in Heaven will appeal to anyone who insists on finding the deepest meaning for their existence based on their own experience.

Creation or Evolution  
Michael Ebifegha
ISBN9781450289023
Were humans created, or did they evolve? How old is the Earth? The debate between science and religion continues to be heated. In Creation or Evolution, Michael Ebifegha examines these two opposed world views within the structure of empirical(实证的) science.

Seeking the Edge  
Dr. Joseph L. Rose
ISBN 9781462031795
Seeking the Edge provides the tools and techniques to find that edge in one’s life. ---driving readers to achieve success whether in your current job, finding a new job, in education, family, or even hobbies.
小题1:Who wrote the story about a little boy and a little mouse?
A．Bill Bosworth.B．Michelle O. Donovan.C．Dr. Joseph L. Rose.D．Gloria Coykendall.
小题2:The ISBN for the book of poems is _______.
A．9781462031795B．9781412027854C．9780595433582D．9781462058679
小题3:What kind of readers will probably like reading More Things in Heaven?
A．Those who are searching for the meaning of life.
B．Those who are trying to be spiritual leaders.
C．Those who study the art of writing.
D．Those who like traveling abroad.
小题4:Which of the following books explores the origin of humans?
A．Seeking the Edge.B．Creation or Evolution.
C．Joshua, Helmut, and Bethlehem.D．More Things in Heaven.
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