问题 解答题

JAC牌货车的运输率是拖拉机的2.5倍,大型集装车的运输率是JAC牌货车的3倍,现有一堆货物,用JAC牌车运,要6小时,如果改用拖拉机运一半,再用大型集装车运另一半,一共要用多少小时?

答案

拖拉机、JAC牌货车、大型集装车的工作效率比为:

1:2.5:2.5×3=2:5:15;

所用时间比为:15:5:2;

拖拉机运这堆货物用时:

15
5
=18(小时);

大型集装车运这堆货物用时:

2
5
=2.4(小时);

一共要用:

18÷2+2.4÷2,

=9+1.2,

=10.2(小时);

答:一共要用10.2小时.

阅读理解

150 Years of Cool

Look in the bedrooms of young people around the world. You will probably find a pair of blue jeans in each room. Jeans are very popular all over the world.

Jeans give you the feeling of comfort, youth and energy. They have long been liked by every person.

Levi Strauss is an American company. It first made blue jeans. The company was founded in 1853 by 24-year-old Levi Strauss. Twenty years later, he made the first blue jeans in the world. The jeans were used as working trousers for the cowboys of the American West. During the Second World War, American soldiers brought blue jeans to Europe and Asia. People there began to wear jeans. Little by little, they become cool.

People from different countries like different styles of jeans. Americans like to wear simple and single-colored jeans, but many Chinese like to wear jeans with lots of different colors.

Jeans now can be seen everywhere: However, in many places, it’s not always good to wear jeans. No matter how good they may look, or what color they are, it’s often not right to wear jeans in formal places. But, when you are out, relaxing and having fun, jeans are the best choice.

小题1:The story is talking about_____________.

A.Levi Strauss

B.young people

C.cool

D.jeans小题2:Levi Strauss made the first blue jeans_____________.

A.when he was 44

B.when he was 24

C.in 1853

D.in 1924小题3:___________ wore jeans after they were first made.

A.American soldiers

B.American cowboys

C.Levi Strauss

D.The people in Europe小题4:Jeans can be cool for nearly 150 years because _____________.

A.they have different styles

B.they have different colors

C.they make us feel youth, comfort and energy

D.they are working trousers.小题5:When you _____________, you’d better not wear a pair of jeans.

A.go to an important meeting

B.go on a trip

C.have a party

D.are having fun

单项选择题