题目内容
By _____, water can be changed into gas.
A.heating? B.being heated? C.having heated? D.heated
B
解析:
介词by后应接动名词作宾语，意为“通过…….”,表示方式。在此句中， water与heat之间是动宾关系，所以应用动名词的被动式。
If you want your land to keep fertile, you must try to stop soil from being carried away by water or wind. When soil is taken away by flowing water or blowing winds we call it soil erosion. Ways have been found to stop soil erosion, and this is known as soil conservation. One way of stopping soil erosion is to grow small plants such as grass. These plants are referred to a cover crops, whose roots hold the soil tightly together. The rain water can not wash away the soil. When trees and tall bushes are planted at the edges of an open field, soil erosion by strong winds can not take place. The trees and b
ushes, which act as a
very big and firm wall, protect the open land from the winds. The way to stoop soil erosion on slopes is to build terraces on the slope of hillside and mountainside. When the slope of a hillside is cut into “step”, water carrying soil can not run straight down the terraces, which are used to slow down the speed of the flowing water containing much soil in it. In this way most of the soil in the water is left behind on the terraces, much soil in it.
【小题1】What takes place in soil erosion?
| A．Flood happens to the fertile land |
| B．A large quantity of the soil loses away gradually. |
| C．Terraces are built on the slope of hillside or mountainside. |
| D．Plants are grown to protect the open land |
A. grass B. trees and bushes C. plants life and an area
E. covering plants that produce grain or vegetables
【小题3】Besides growing small plants, another method to fight against soil erosion is to ___________.
| A．build terraces | B．build walls | C．plant trees | D．plant tall bushes |
| A．because their roots hold soil tightly |
| B．to stop soil from being blown away by winds. |
| C．Because soil erosion causes terrible damages to crops |
| D．To keep the balance of nature |
tle of the passage?| A．What Causes Soil Erosion |
| B．The Importance of Erosion |
| C．Rain Erosion and Wind Erosion |
| D．Erosion and the Way of Tight against Erosion |
Cholera is a water-borne disease that is spread through polluted water and food. Cholera is an illness caused by the bacterium. It produces a poison that causes a painless , watery diarrhea( 痢疾) that can quickly lead to severe dehydration（脱水） and death if treatment is not given. Most persons infected with cholera do not become ill, although the bacterium is present in their waste for 7-14 days. When this illness does strike, more than 90% of the time is not severe and is difficult to tell from other types of diarrhea. Less than 10% of sick persons develop cholera with signs of moderate or severe dehydration.
A person may get cholera by drinking water or eating food polluted with the cholera bacterium. The disease can spread rapidly in areas without the proper treatment of drinking water. The cholera bacterium may also live in the environment in dirty rivers and coastal waters. Shellfish eaten raw have been a source of cholera. Therefore, the disease is not likely to spread directly from one person to another.
Cholera can be simply and successfully treated by immediate replacement of the fluid and salts lost through diarrhea. Patients can be treated by being given a mixture of sugar and salt to be mixed with water and drunk in large amount. Antibiotics(抗生素) shorten the course and decrease the severity of the illness. To avoid cholera, we should eat well-cooked food instead of raw food.
【小题1】If a person infected with cholera less than 7 days，he would probably .
A. die B. become sick C remain healthy D suffer from watery diarrhea
【小题2】Which statement is true according to the passage?
A Cholera can spread directly from one person to another.
B. Eating raw food can help stop cholera.
C. Cholera is caused by watery diarrhea.
D. Polluted water and food can help spread cholera.
【小题3】 Cholera can be treated by .
| A．replacing the blood in the body. |
| B．eating a lot of water mixed with sugar and salt and using antibiotics. |
| C．eating a large amount of sugar and salt |
| D．drinking a lot of water and eating a large amount of food. |
A inject antibiotics B eat the food thoroughly cooked
C eat raw food D. avoid meeting other people
NASA’s Mars detector (探测器), Opportunity, succeeded in finding signs that water once existed on the planet. Opportunity landed on Mars in January. Scientists now believe that the planet could once have supported life.
This discovery was chosen by Science, one of the world’s leading magazines, as the most important scientific achievement of 2004 last Friday.
“This little, wheeled, one-armed box went around another planet and has done something no human has ever managed,” according to Science. “It has discovered another place in the universe where life could once have existed.”
“Although we still can’t say that life could have existed in this environment, it is now certain that there was water on Mars,” said Steve Squyres, one of the scientists working on the Mars mission. The evidence comes from pictures and chemical readings taken by Opportunity. It includes marks on rocks like those caused by flowing water on Earth and salty chemicals like those found in dried-out sea-beds. Scientists said the new evidence proved beyond doubt that water has existed on Mars. But it is still unknown whether the water on Mars was like an ocean or justice.
While Opportunity has not found any signs of life, the presence of water means life is possible. “In everything we know about life on Earth, there is no example without liquid water,” Squyres said. “So water is important for the search for life on Mars.”
Researchers agree that a future mission (任务) should bring back physical samples (样品). But some scientists worry about the risk that this could introduce dangerous foreign creatures to Earth. “The problem here is how to get the samples back,” Squyres replied. “I think it is our responsibility to limit any risk.”
1.________ prove that water existed on Mars.
|
A．The physical samples with salty chemicals |
|
B．The marks on rocks and salty chemicals |
|
C．Scientific achievements of 2004 |
|
D．Creatures from Mars |
2.Which of the following is TURE according to the text?
|
A．It is now certain that there was water on Mars. |
|
B．The water on Mars was like an ocean. |
|
C．Evidence of life on Mars has been found. |
|
D．Search for life on Mars is a great risk to humans. |
3.How did scientists draw the conclusion that there was water on Mars?
|
A．The world’s leading magazine has announced the fact. |
|
B．Scientists have taken many pictures and chemical readings on the Mars. |
|
C．Astronauts have got some rocks from Mars. |
|
D．Scientists have made a study of the pictures and readings sent back by Mars detector. |
4.It can be inferred that, if the creatures from Mars came to Earth, ________.
|
A．they would be kind to humans |
|
B．they would be cruel to humans |
|
C．they would be a great danger to Earth |
|
D．it would be hard to say whether it would be a good news or bad news |