问题 选择题

关于惯性,下列说法中正确的是( )

A.材料不同的两个物体放在地面上,用一个相同的水平力分别推它们,则难以推动的物体惯性大

B.在完全失重的情况下,物体的惯性将消失

C.两个质量相同的物体,不论速度是否相同,受力是否相等,其惯性一定相同

D.抛出去的标枪、手榴弹等是靠惯性向远处运动的

答案

CD

题目分析:A、材料不同的两个物体放在地面上,用一个相同的水平力分别推它们,则难以推动的可能是受到的摩擦力大;错误

B、物体的惯性与运动状态无关;错误

C、质量是惯性的唯一量度,与运动状体和是否受力无关;正确

D、抛出去的标枪、手榴弹等有保持原来运动状体的性质,依靠惯性向远处运动;正确

故选CD

点评:惯性是物体的一种属性,只与物体的质量有关,与物体的受力和运动状态无关,一切物体均有惯性。

单项选择题
阅读理解

阅读理解。

     There is a saying"Beauty is in the eye of the beholder." What one person considers beauty may not be

beautiful to another. When we talk about beauty in people, we often refer to their physical attractiveness. Of

course, a beautiful or handsome face is pleasant to look at. But to me beauty is not only something that pleases

the eyes, but also pleases the other senses and the mind. I think true beauty makes you see beyond the lovely

sight. It will give you insight (深刻的了解) or realization of something interesting beyond just the outward

appearance.

     The most memorable "beautiful people" are those who have attractive personalities behind the pretty faces.

In one of my previous classes, there were two beautiful girls, Sue and Lin. Both had almost perfect faces and

slender (纤细的) figures. But Lin was used to getting her own way. She felt that her looks could help her get

anything she wanted, especially among the boys. Sue, on the other hand, treated her beauty in a matter of-fact

way and she was nice to everyone. She was also a member of the debating team. Her personality was mostly

accepted by others and it made her a more outstanding beauty than Lin.

     Inner beauty is another kind of beauty that attracts people greatly. People who have this kind of beauty have

attained (获得) inner peace. They care about their fellowmen, and try to right the injustices in this world. Two

well-known personalities who exemplify this are Nelson Mandela and Mother Theresa. Mandela is willing to

sacrifice his life and freedom to obtain equal rights for the blacks in South Africa. Mother Theresa's mission is

to help the poorest of the world's poor. This inner beauty makes the world a better place.

1. When we talk about beauty in people, we often refer to _____. [ ]

A. the beauty of eyes

B. something beyond the lovely sight

C. something that pleases our eyes

D. inner beauty

2. What does the underlined sentence "Beauty is in the eye of the beholder" mean? [ ]

A. Beauty is a matter of a person's taste and judgment.

B. Beautiful people are very popular.

C. Everybody hopes for beauty.

D. Beauty attracts people's eyes.

3. According to the passage, why did the author think Sue was more beautiful than Lin? [ ]

A. Sue had a perfect face.

B. Sue had a good character.

C. Sue became more and more slender.

D. Lin treated her beauty in a matter-of-fact way.

4. What's the author's opinion on beauty? [ ]

A. Beauty is a perfect face and a slender figure.

B. Beauty is something that pleases the eyes.

C. Beauty is an attractive personality behind the pretty faces.

D. Inner beauty doesn't attract people.