Scientists in Colombia have trained a team of rats to help remove land mines from the countryside. Land mines are small bombs hidden in the ground and designed to explode(爆炸) when someone steps on them.
When trained, the rats can smell special metals in the mines and then signal(發(fā)信號) to their human team. Then why use rats for such an important job?
In the past, dogs have been used to find bombs. Rats have a good sense of smell and can respond to orders, just like dogs do. But rats are much lighter than dogs. They stand less of a chance of setting off the mines, which explode under a certain amount of weight. What’s more, the best rats are cheaper to keep than dogs. It costs about the same amount of money to take care of one dog as it does 70 rats.
The rats have already been used in Tanzania, an African country with many land mines. Luisa Fernanda Méndez and her team in Colombia are training the even lighter Wistar rats. These are the white rats with red eyes that scientists often use in laboratory experiments. “They even train their babies to perform their jobs, which saves us a lot of time, ” Méndez said.
Colombia has the second-highest rate(比率) of deaths from land mine accidents in the world. Last year, land mines killed 695 people — 56 of whom were children. A criminal group called the Revolutionary Armed Forces of Colombia, or FARC, as well as other organizations, have placed the mines. FARC are strongly against Colombia’s government. The group has placed mines all around its own bases and in many places in the countryside.
In the past, the Colombian government hired peasants and poor farmers to find mines. Many of them died trying to find the well-hidden bombs.
Colombian police official Erick Guzmán hopes the team of rats can come to the rescue(援救). “These rats will be a great help,” he said.
小題1:How do rats help to find land mines?
A．By their special sight. B．By their light weight.
C．By their sense of smell.D．By their excellent hearing.
小題2:The advantage of rats over dogs in finding bombs is that _____.
A．they are cleverer.
B．they run faster
C．they have a better sense of smell
D．they don’t make mines explode as easily
小題3:The underlined word “They” may refer to ______.
A．scientistsB．Wistar rats
C．dogsD．Méndez and her team
小題4: What is the passage mainly about?
A．Specially-trained rats help clear land mines.
B．People in Tanzania are suffering from land mines.
C．Dogs are no longer used to find land mines.
D．Land mines have become a great danger to Colombians.

小題1:C
小題2:D
小題3:B
小題4:A

試題分析：本文敘述了科學(xué)家們在哥倫比亞已經(jīng)訓(xùn)練一組老鼠幫助在農(nóng)村清除地雷。以前用狗來幫助清除地雷，老鼠的優(yōu)勢他有靈敏的嗅覺，能夠聞出特殊的金屬味，并且他們的體重輕引爆地雷的可能性小，還有養(yǎng)它們的費用比養(yǎng)狗的費用低。
小題1:細(xì)節(jié)理解題。根據(jù)the rats can smell special metals in the mines and then signal(發(fā)信號) to their human team.老鼠可以聞到特殊的金屬在煤礦,然后給人發(fā)信號，故選C。
小題2:細(xì)節(jié)理解題。根據(jù)But rats are much lighter than dogs. They stand less of a chance
of setting off the mines,但是老鼠比狗更輕。他們的體重輕引爆地雷的可能性小，故選D。
小題3:詞義猜測題。根據(jù)The rats have already been used in Tanzania, an African country with many land mines. Luisa Fernanda Méndez and her team in Colombia are training the even lighter Wistar rats. These are the white rats with red eyes that scientists often use in laboratory experiments.上文提到的是Wistar rats ，故選B。
小題4:主旨大意題。根據(jù)全文的內(nèi)容主要說的是受過特殊訓(xùn)練老鼠幫助清理地雷，故選A。
點評：主旨大意題的難度較大，此類題目一般不易直接找到答案，最簡單的方法是仔細(xì)研究文章開頭的一二句，因為他們常是文章的主題句，然后，快速瀏覽文章首句和結(jié)尾句。如果第一句的主題不明，可注意結(jié)尾是否有概括總結(jié)，對選項要注意全面性和概括性。
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Influenced by movies and popular novels, most people see sharks as people-eating monsters. This is far from the truth. Every year, a few types of shark injure about 100 people worldwide and kill about 25. Most attacks are by great white sharks, which often feed on sea lions and other marine（海洋的） mammals. They sometimes mistake human swimmers for their normal prey, especially if they are wearing black wet suits.
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A．People kill sharks for food.
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C．People kill sharks out of fear.
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How Do Animals Catch their ZZZ's（打鼾聲）？
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Dolphins live underwater, but must come to the surface to breathe． Scientists now believe that dolphins may sleep with only half their brain, while the other half stays awake to keep them safe and breathing． Seals also do this, lying on their sides on the surface of the water with one flipper underwater paddling to keep their noses above the surface． Some ducks may also have this ability, and actually sleep with one eye closed and one eye open．
小題1:How does a chameleon protect itself while sleeping?
A．By changing its body colors
B．By hanging out over a pond．
C．By sleeping with half their brain．
D．By making beds with branches．
小題2:Why will not birds fall when they are at rest?
A．They build nests and sleep in them．
B．They fall asleep automatically．
C．They have a loose tendon in their legs．
D．They lock their feet around a branch．
小題3:How do dolphins breathe?
A．They breathe underwater．
B．They come to the surface to breathe．
C．They breathe underwater or come to the surface to breathe．
D．We don't know．
小題4:What does the writer intend to tell us?
A．The cleverest animal is the gorilla because it can make beds．
B．Differences in habitat can lead to different living habits．
C．The ways animals catch their ZZZ's are pretty much the same．
D．In order to protect themselves most animals choose not to sleep

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