题干

小汽车已经进入普通家庭,如图所示.下列说法正确的是(   )

A:汽车静止在水平地面上,受到的重力与地面对它的支持力是一对平衡力

B:汽车静止在水平地面上,汽车对地面的压力与地面对它的支持力是一对平衡力

C:在同一水平路上,汽车加速运动时受到的牵引力小于受到的阻力

D:汽车高速行驶时对地面的压力小于静止时对地面的压力

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答案(点此获取答案解析)

A,D

同类题5

Choose the best topic from A to F according to the meaning of the passage.

 A"Gap Year" is a period of time when a student takes a break before going to university. It is often spent travelling or working. It can give young people useful learning experiences and new skills. It's very popular in foreign countries.____ 

 Although you don't have to go abroad to experience gap years, most gap year students catch the chance to travel abroad. You are able to work out who you are and what you are for. The experiences of different cultures offer you interesting lessons. You can learn more about the world and get to know yourself better.____ 

A gap year is not only a time to take a vacation, but also a time to face challenges. Gap year students usually work, volunteer or take service projects. You have to learn how to get along in the real world. This process isn't always easy, but it is an important part of growing up. Only in this way can you enjoy life and have fun.____ 

 There's a common thought that gap years are only for rich students, but it's not true. Actually, taking a gap year can save your money. Gap year students often take a part-time job. Besides, at the end of a gap year, students are much more likely to know what to study in college. Clear learning goals can keep the students working hard instead of wasting time and money playing.____ 

 Imagine an admission officer trying to admit(录取) only one between two students. Both of them are excellent and have high grades. However, one student has much practical experience or has volunteered in his vacation. Who do you think the admission officer will choose?____ 

A. Learn about the world and yourself          

B. The meaning of "Gap Year"

C. Take a part-time job                

D. Improve your college admission chances

E. Save money                     

F. Face challenges and have fun