Frogs are animals that can live both in water and on land. There are more than 5,000 kinds of frogs on the earth. The earliest known frogs lived about 190 million years ago and the frogs today still l 题目和参考答案——青夏教育精英家教网—

题目内容

Frogs are animals that can live both in water and on land. There are more than 5,000 kinds of frogs on the earth. The earliest known frogs lived about 190 million years ago and the frogs today still look the same. Here are some fun things that you might not know about frogs. Enjoy!

The Biggest and the Smallest Frogs

Some frogs can be very big. The biggest kind of frog is the Goliath Frog in West Africa. Its body can be nearly 30cm long, about the size of a large cat. The Gold Frog and the Poison Frog are the smallest frogs in the world. They are less than 1cm long. Though the Poison Frog is very small, it is not weak at all. It is dangerous. Any animal that eats it will die very soon.

The Best Jumpers

Frogs are very good at jumping. They developed jumping legs so that they would not be eaten by other large animals. Using their big strong legs, more frogs can jump over 20 times their own length. It is like a person jumping over about 30,48. The Australian Rocket Frog can even jump over 2m, which is 50 times its body length(5.5cm). That might be the reason why frogs are called the best jumpers on the earth.

The Cryogenic Animal

Some frogs like the Common Wood Frog have a special ability to live in very cold places. When the temperature goes down, they become ice frogs. 2/3of their body water freezes. Their hearts stop, and their breathing stops too. You may think they are dead, but in fact they are not. Maybe we humans can learn the way that the frogs do for medical purpose.

1.The earliest frogs lived about ________ million years ago.

A. 20 B. 30 C. 50 D. 190

2.The Gold Frog is one of the ________ frogs on the earth.

A. smallest B. biggest C. strongest D. weakest

3.________ can jump over 2m.

A. The Goliath Frog B. The Common Wood Frog

C. The Poison Frog D. The Australian Rocket Frog

4.What will happen to a Common Wood Frog at very low temperature?

A.It will die very soon. B. It will be an ice frog.

B.It will become dangerous. D. It will become very small

【答案】

1.D

2.A

3.D

4.B

【解析】

试题分析：本文叙述了青蛙是水陆两栖动物，世界上有5000多种青蛙。最早的青蛙生活在大约1亿九千万年前，和今天的青蛙看上去一样。并一一介绍了最大的青蛙，最小的青蛙，跳得最远的青蛙和能承受最低温度的青蛙。

1.细节理解题。根据第一段“The earliest known frogs lived about 190 million years ago”可知本题选D。

2.细节理解题。根据第二段“The Gold Frog and the Poison Frog are the smallest frogs in the world.”可知本题选A。

3.细节理解题。根据第三段“The Australian Rocket Frog can even jump over 2m,” 可知本题选D。

4.细节理解题。根据第四段“When the temperature goes down, they become ice frogs.” 可知本题选B。

考点：科普环保类阅读。

练习册系列答案

相关题目

A breathtaking trick potentially left over from our ancestors might be found in us — the ability to sense oxygen through our skin.
Amphibians, animals such as frogs that can live both on land and in water, have long been known to be capable of breathing through their skin. In fact, the first known lungless frog that breathes only through its skin was discovered recently in the rivers of Borneo.
Now the same oxygen sensors found in frog skins and in the lungs of mammals (哺乳动物) have unexpectedly been discovered in the skin of mice.
“No one had ever looked,” explained Randall Johnson, a biologist researcher.
Mice and frogs are quite distant relatives, so the fact they have these molecules (分子) in common in their skin suggests they might well be found in the skin of other mammals, such as humans.
“We have no reason to think that they are not in the skin of people too,” Johnson said.   These molecules not only detect oxygen, but help increase levels of vital red blood cells, which carry oxygen around the body. Normal mice breathing in air that is 10 percent oxygen—a dangerously low level similar to conditions at the top of Mount Everest, and about half that of air at sea level. However, mice that had the oxygen sensor HIF-1a genetically removed from their skin failed to produce this hormone (荷尔蒙) even after hours of such low oxygen.
These findings, if they hold true in humans, suggest one could raise the level of oxygen circulating inside the body. This could help treat lung diseases and disorders such as anemia (贫血症) without injecting drugs, which make up a multibillion-dollar market, Johnson said.
Athletes also often try to get more oxygen delivered to their muscles in order to improve their performance. They often do this by training at high altitudes or in low-oxygen tents. The new study suggests they might want to expose their skin as well as breathing in low-oxygen air to improve their performance. “It’s hard to say what exactly might be done, however—there’s a lot we don’t know yet,” Johnson explained.
The scientists detailed their findings in the April 18 issue of the journal Cell.
49. Which of the following statements is TRUE according to the passage?
A. Johnson believes that Oxygen sensors also exist in human skin.
B. People have to surf the Internet to read detailed findings.
C. It has been proved that these findings help treat lung diseases.
D. It has long been expected oxygen sensors exist in mice’s skin.
50. One of the functions of the molecules mentioned above is _______.
A. carrying oxygen around the body                   B. improving athletes’ performance
C. detecting oxygen                                          D. increasing level of oxygen
51. What is Johnson’s attitude to the application of the findings to the athletes’ training?
A. Negative                  B. Doubting                  C. Positive             D. Hesitating
52. The best title of the passage may be _______.
A. Great Findings Benefits Athletes A Lot
B. Frogs And Mice Are Distant Relatives
C. First Known Animal Breathes Through Skin
D. Humans Might Sense Oxygen Through Skin

If you go out to the fields at night in spring or summer, you can hear frogs singing 1.__ (joy) here and there. It seems as if they were performing a field symphony.

The frog is a good and useful creature that benefits human beings. They can catch fast-moving insects. Each frog eats a large number of pests that are harmful _2.__ crops. This little creature is regarded __3._ “the natural enemy of pests”．

4._ now frogs are getting fewer and fewer. This is because they are killed and put on the table as a delicious dish by their chief enemy, human beings. It is __5.__ shameless and cruel act, isn’ t it？_6._ cause responsible for the rapid reduction of frogs is that farmers use insecticides (杀虫剂) to kill pests and frogs get killed as a result of drinking poisoned water __7._ eating poison-killed insects.

Something must be done without delay _8._(save) frogs. If we don’t punish those __9._ sell and kill frogs to make money, then one day all of us __10.__(punish) by nature for failing to keep the balance of nature.

A breathtaking trick potentially left over from our ancestors might be found in us — the ability to sense oxygen through our skin.

Amphibians, animals such as frogs that can live both on land and in water, have long been known to be capable of breathing through their skin. In fact, the first known lungless frog that breathes only through its skin was discovered recently in the rivers of Borneo.

Now the same oxygen sensors found in frog skins and in the lungs of mammals (哺乳动物) have unexpectedly been discovered in the skin of mice.

“No one had ever looked,” explained Randall Johnson, a biologist researcher.

Mice and frogs are quite distant relatives, so the fact they have these molecules (分子) in common in their skin suggests they might well be found in the skin of other mammals, such as humans.

“We have no reason to think that they are not in the skin of people too,” Johnson said.

These molecules not only detect oxygen, but help increase levels of vital red blood cells, which carry oxygen around the body. Normal mice breathing in air that is 10 percent oxygen—a dangerously low level similar to conditions at the top of Mount Everest, and about half that of air at sea level. However, mice that had the oxygen sensor HIF-1a genetically removed from their skin failed to produce this hormone (荷尔蒙) even after hours of such low oxygen.

These findings, if they hold true in humans, suggest one could raise the level of oxygen circulating inside the body. This could help treat lung diseases and disorders such as anemia (贫血症) without injecting drugs, which make up a multibillion-dollar market, Johnson said.

Athletes also often try to get more oxygen delivered to their muscles in order to improve their performance. They often do this by training at high altitudes or in low-oxygen tents. The new study suggests they might want to expose their skin as well as breathing in low-oxygen air to improve their performance. “It’s hard to say what exactly might be done, however—there’s a lot we don’t know yet,” Johnson explained.

The scientists detailed their findings in the April 18 issue of the journal Cell.

1.Which of the following statements is TRUE according to the passage?

A．It has long been expected oxygen sensors exist in mice’s skin.

B．People have to surf the Internet to read detailed findings.

C．It has been proved that these findings help treat lung diseases.

D．Johnson believes that Oxygen sensors also exist in human skin.

2.One of the functions of the molecules mentioned above is _______.

A． increasing level of oxygen B．improving athletes’ performance

C．detecting oxygen D．carrying oxygen around the body

3.What is Johnson’s attitude to the application of the findings to the athletes’ training?

A． Hesitating B．Doubting C．Positive D．Negative

4.The best title of the passage may be _______.

A． Humans Might Sense Oxygen Through Skin

B．Frogs And Mice Are Distant Relatives

C．First Known Animal Breathes Through Skin

D．Great Findings Benefits Athletes A Lot

Experts say the American state of Hawaii has been invaded (入侵)by a small frog called the coqui (ko--kee). There may be millions of the small frogs in Hawaii. However, they do not belong there. They are normally found in the southeastern United States. The coqui frogs are harming Hawaii’s environment. And the extremely loud noise they make is causing problems for Hawaiian citizens and visitors.

The coqui invaders arrived in Hawaii about ten years ago. They were believed to have been brought in accidentally in shipments of plants from Florida. Their number has sharply increased. They have quickly spread around the Hawaii Islands hidden in plants.

The coqui is a brown frog about five centimeters long. During the day, the frogs hide in wet protected areas, such as under plant leaves. At night, the frogs move onto trees to feed, call to females and mates. The call of the male coqui sounds like. Ko kee! Ko kee!

In the southeastern United States, local people celebrate coqui frogs. But in Hawaii, the foreign frog has been considered as a harmful animal. The coqui frogs are a major danger to Hawaii’s environmental system. The frogs eat thousands of insects (昆虫)every night. These insects are important for the reproduction of plants. The insects also are important food for Hawaii’s native rare birds. The frogs also are affecting the tourism industry in Hawaii. Increasing numbers of hotels, visitors and local people have been annoyed by the loud calls made by male coqui frogs to female frogs. At night, the noise often makes it difficult for people to sleep.

The frogs do not have any natural enemies in Hawaii to reduce their population size. The warm weather permits them to lay eggs all year long. There are many efforts in Hawaii designed to stop the spread of the coqui. It is a crime to transport ,sell or release(释放)the frogs there.

The Hawaii Department of Agriculture is trying to find an effective chemical that can be safely used to kill the frogs. For now, the frogs may only be caught by hand. The Hawaii Department of Agriculture says the greatest danger to the economy and environment of the state is from harmful species, like the coqui.

1.The statement that can best summarize the main idea of the passage is .

A．the coqui invaders have seriously affected the tourism industry in Hawaii

B．it is not permitted to transport, sell or release the coqui frogs in Hawaii

C．the coqui invasion has serious effects on the economy and environment in Hawaii

D．great efforts have been made by the Hawaii people to kill the coqui

2.The coqui frogs originally arrived in Hawaii .

A．by chance B．at the request of all the local citizens

C．as a gift D．as goods demanded in the local market

3.Visitors to Hawaii don’t like the coqui frogs mainly because .

A．they are a big danger to the environmental system there

B．the loud noise made by the frogs bother their rest at night

C．they affect the reproduction of the local plants and insects

D．visitors could no longer see the native rare birds because of them

4.The two factors leading to the rapid spread of coqui frogs in Hawaii are .

A．the frogs’ habit and the environment in Hawaii

B．the large number of the insects and the plants in Hawaii

C．the geographic location of Hawaii and its tourism industry

D．the warm weather there and the frogs’ lack of natural enemies

试题分类