56. Which of the following is the best title for this passage?

A. Never Say Die.

B. Sam Patch and Falls.

C. Conquer Niagara Falls

D. A Hero

57. What is the general idea of this passage?

A. Genesee Falls is a dangerous place.

B. Sam Patch jumped at Niagara Falls.

C. There's no mistake in Sam Patch.

D. Sam Patch was a popular leaper.

58. This passage implies that ______________.

A. Sam Patch is still alive

B. Sam Patch was a foolish man

C. Sam Patch loved to get a lot of attention

D. jumping fro high bridges was not very dangerous

B

The elephant is the largest of all land animals. It can reach a height of eleven feet and weigh nearly six tons. The African elephant can also boast the biggest ears in the world. They can grow as large as three-and-a-half feet across. You might think that a gigantic animal like the elephant wouldn't have much to worry about, but it has its problems too. And its huge ears can help it to deal with many problems ranging from pesky insects to great danger.

The ears are very effective fans that can be used to drive away flies. The elephants' huge ears also help them hear everything that's happening nearby. A mother ele­phant might hear the approach of a dangerous lion that would kill her children.

The elephants' great size can sometimes present a heat problem. The larger an object, the harder it is for it to lose heat. Elephants live on the hot plains of Africa, where keeping cool is not an easy task. Elephants' huge ears help them cool their bodies so they can survive in the heat. The large surfaces of the ears have many blood vessels that are very close to the surface of the skin. Blood that is closer to the surface cools more easily.

The most impressive use of the ears, though, is seen in an elephant's threat dis­play. When trying to threaten another animal, the elephant bellows and charges with both ears spread wide. This makes the huge beast look almost twice as large as it really is. Few enemies would dare to stand up to anything that huge.

59. Which of the following is the best title for this passage?

A. The Use of the Ears.

B. Keeping Cool in Africa.

C. Survival on the African Plains.

D. The Elephant's Threat Display.

60. We can conclude that if elephants did not have big ears they would probably __________.

A. see better

B. be smaller

C. not be able to survive

D. not live in Africa

61. The author calls the elephant's threat display “impressive.” This means that it is _________.

A. interesting

B. admirable

C. amusing

D. normal

C

Only one animal can walk 200 miles without stopping once to rest. It would take a person two days and two nights to walk this far, and only one man has ever done it without stopping. What animal has such endurance (耐力)? The camel! The camel is famous for something else, too. It can cross an entire desert without a single drink of water. Its body is built in a special way to help it store water and food.

A person has just one stomach, but a camel has quite a few. Within each stomach are layers and layers of cells. These cells are like tiny water balloons, storing liquids until the camel needs them. When the camel drinks, the cells grow larger and larger. For a whole week, they can keep the animal's thirst away by sending water to all parts of its body.

And did you ever wonder why the camel has a hump (驼峰)? The hump is a storage place for fat. Because it has this storage area, the camel does not need to eat very often. When the animal needs energy, the layers of fat serve as fuel to keep it going on the long, hot days in the burning sun.

The camel has one other gift that makes it well suited to arid regions. This gift is its nose. A camel can smell a water hole from miles away!

When a camel moves it sways (摇摆) from side to side like a ship on a wavy ocean. Because of this swaying action, the camel has been called the ""Ship of the Desert.""

62. This passage is mainly about .

A. long‑distance walking

B. mysterious ships

C. desert animals

D. the camel

63. Where do camels keep the water they have taken in?

A. In the stomach together with the food they ate.

B. In the cells of their stomachs.

C. In the hums on top of their backs.

D. In the bags they carry on their backs.

64. The camel's hum is storage place for .

A. fat

B. muscles

C. extra water

D. body sugars

65. We can conclude from this passage that camels .

A. will always be useful

B. like to carry heavy loads

C. feel at home in the desert

D. look like ships from a distance

D
The nuclear age in which the human race is living, and may soon be dying, began for the general public with the dropping of an atom bomb on Hiroshima on 6 August 1945. But for nuclear scientists and for certain American authorities, it had been known for some time that such a weapon was possible. Work towards making it had been begun by the United States, Canada and Britain very soon after the beginning of the Second World War. The existence of possibly explosive forces in the nuclei of atoms had been known ever since the structure of atoms was discovered by Rutherford.
An atom consists of a tiny core called the `nucleus' with attendant electrons circling round it. The hydrogen atom, which is the simplest and lightest, has only one electron. Heavier atoms have more and more as they go up the scale. The first discovery that had to do with what goes on in nuclei was radio-activity, which is caused by particles being shot out of the nucleus. It was known that a great deal of energy is locked up i

上一页  [1] [2] [3] [4] [5] 下一页