There is an old story about a king and his daughter. The king asked his daughter how much she loved him. She said that she loved him as much as she loved salt. Her answer made the king sad. Salt is a simple thing, and it is very common. So the king thought his daughter didn't care about him. But the king was wrong. Salt might be common, but it is very important. Throughout history, salt has caused wars. So why do people care so much about salt?

Salt has many uses. Our bodies need salt. If we don't have enough, our body can't work properly. We put salt on icy roads to make them safe. We also use salt to produce other products. Products like paper, glass, rubber and soap depend on salt. But for many years, salt's most important job was preserving(保存)food.

Like other living things, most bacteria(细菌)that cause food to spoil need water to survive. Salt absorbs large amounts of water, so most bacteria cannot live in a salty environment. As a result, salt has the ability to preserve almost anything. For much of human history, this ability has made salt treasured. Every ancient culture from Egypt to China depended on salt. Even today, we compare hardworking, useful people to salt by calling them "the salt of the earth".

For centuries, salt was also hard to get. The combination(组合)of usefulness and rarity made it extremely expensive. Since almost everyone needed salt, the salt trade was an important business. Salt could even be used like money. In fact, the word salary(工资)comes from the word salt. And valuable people are still described as being "worth their salt." Today, salt is easy to get. It is no longer expensive, but it is still both important and useful.

1.In the first paragraph, the writer is trying to make readers .

A. become interested in the old story B. understand the importance of salt

C. fall in love with salt D. understand the daughter's love to salt

2.Which of the following is NOT true according to the article?

A. Salt is very common, but it has many uses.

B. Salt was so valuable that it was once used like money.

C. Although salt is cheap now, it's still important and useful

D. We can use salt to produce all the products we need.

3.What's the meaning of the underlined word "rarity"?

A. the quality of being rare B. the quality of being important

C. the quality of being common D. the quality of being useful

Many teachers believe that hands-on experiences are the best way to learn. A group of students in the United Sates is putting that belief to the test.

The students are from the Stevens Institute of Technology. They successfully designed and built a robot for discovering mines at the bottom of the sea. The underwater robot is called Perseus II. It costs about $15,000 to build. The students made the robot to answer a challenge from the U.S. Department of Defense(国防部).

The students use a video game controller to direct its movements. Devices known as

thrusters enable the robot to go up, down and toward its target in the water. Video cameras on the robot send images back to a computer through a 13-meter-long cable(电缆). Perseus II also has a set of lasers(激光), they are used to measure the size of an object.

The robot is the creation of five college students. They worked for over six months to design and build Perseus II.

"Their goal was to go down and find the mine and not only just find it but provide information to an expert on the surface so he or she could make a decision whether it was something dangerous or not before they removed it," Michael DeLorne said.

Perseus II was successfully tested in Florida with similar robots built at other engineering schools. In a separate development, new students at the Stevens Institute of Technology have already started on the next project. It is a flying vehicle they are calling Perseus III.

1.Why did the five college students make the robot?

A. To go up, down and toward its target underwater.

B. To provide information to an expert on the surface.

C. To answer a challenge from the Department of Defense.

D. To prove hands-on experiences is the best way to learn.

2.Which of the following is NOT part of Perseus II?

A. a set of lasers B. a computer

C. video cameras D. a video game controller

3..What does the word “mine” in Paragraph 5 most probably mean ?

A. 宝藏 B. 海鱼 C. 矿井 D. 水雷

4.What can we infer(推断) about Perseus III according to the passage?

A. Perseus III may be used in the sky.

B. Perseus III has been successfully tested in Florida.

C. Perseus III will cost more money and time.

D. Perseus III and Perseus II are made by the same students.

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网