— I’m dead tired. I can’t walk any farther, Jenny.

— _______, Tommy. You can do it!

When an ant dies, other ants move the dead insect out. Sometimes, the dead ant get moved away very soon—within an hour of dying. This behavior is interesting to scientists, who wonder how ants know for sure—and so soon—that another ant is dead.

One scientist recently came up with a way to explain this ant behavior. Dong-Hwan Choe is a biologist. Choe found that Argentine ants have a chemical on the outside of their bodies that signals to other ants, “I’m dead—take me away.”

But there’s a twist to Choe’s discovery. Choe says that the living ants—not just the dead ones—have this death chemical. In other words, while an ant crawls around, perhaps in a picnic or home, it’s telling other ants that it’s dead.

What keeps ants from dragging away the living ants？Choe found that Argentine ants have two additional chemicals on their bodies, and these tell nearby ants something like, “Wait—I’m not dead yet.” So Choe’s research turned up two sets of chemical signals in ants: one says, “I’m dead,” and the other set says, “I’m not dead yet.”

Other scientists have tried to figure out how ants know when another ant is dead. If an ant is knocked unconscious, for example, other ants leave it alone until it wakes up. That means ants know that unmoving ants can still be alive.

Choe suspects that when an Argentine ant dies, the chemical that says “Wait-I’m not dead yet” quickly goes away. Once that chemical is gone, only the one that says “I’m dead” is left. “It’s because the dead ant no longer smells like a living ant that it gets carried to the graveyard, not because its body releases(释放) new unique chemicals after death,” said Choe. When other ants detect the “dead” chemical without the “not dead yet” chemical, they drag away the body.

Understanding this behavior may help scientists figure out how to stop Argentine ants from invading new places and causing problems. Choe would like to find a way to use the newly discovered chemicals to spread ant killer to Argentine ant nests.

The ants’ removal behavior is important to the overall health of the nest. “Being able to quickly remove dead individuals and other possible sources of disease is extremely important to all animals living in societies, including us,” says Choe. “Think about all the effort and money that we invest daily in waste management.”

1.The underlined word “twist” in Paragraph 3 means             .

A．an unexpected change                   B．a clear mistake

C．an important key                        D．a shocking conclusion

2.Ants judge whether another one is dead or not depending on            .

A．the sense of taste                       B．the sense of smell

C．the sense of touch                      D．the sense of sight

3.The result of the research can be used to            .

A．kill troublesome pests

B．solve the problem of endangered species

C．prevent further expansion of the ants’ territory

D．keep the balance of nature

4.Why is it important to remove dead individuals?

A．Because it is easier to manage the living.

B．Because it can save money to deal with the waste.

C．Because it can provide more space for the living.

D．Because it can keep the living from suffering disease.

5.What might be the best title of the text?

A．Dead or living? It is easy to judge

B．Pulling away the dead ants is a difficult task

C．Ant nests have great undertaking capacity

D．Leaving it alone or taking it away? Ants feel puzzled

 — You failed again in the maths exam yesterday.
—Don’t tell Dad about it; if he knows that, I’m_______dead. 
A. as well as     B. as much as         C.as good as     D. as many as

When an ant dies, other ants move the dead insect out. Sometimes, the dead ant get moved away very soon—within an hour of dying. This behavior is interesting to scientists, who wonder how ants know for sure—and so soon—that another ant is dead.
One scientist recently came up with a way to explain this ant behavior. Dong-Hwan Choe is a biologist. Choe found that Argentine ants have a chemical on the outside of their bodies that signals to other ants, “I’m dead—take me away.”
But there’s a twist to Choe’s discovery. Choe says that the living ants—not just the dead ones —have this death chemical. In other words, while an ant crawls around, perhaps in a picnic or home, it’s telling other ants that it’s dead.
What keeps ants from dragging away the living ants? Choe found that Argentine ants have two additional chemicals on their bodies, and these tell nearby ants something like, “Wait—I’m not dead yet.” So Choe’s research turned up two sets of chemical signals in ants: one says, “I’m dead,” and the other set says, “I’m not dead yet.”
Other scientists have tried to figure out how ants know when another ant is dead. If an ant is knocked unconscious, for example, other ants leave it alone until it wakes up. That means ants know that unmoving ants can still be alive.
Choe suspects that when an Argentine ant dies, the chemical that says “Wait- I’m not dead yet” quickly goes away. Once that chemical is gone, only the one that says “I’m dead” is left. “It’s because the dead ant no longer smells like a living ant that it gets carried to the graveyard, not because its body releases new unique chemicals after death,” said Choe. When other ants detect the “dead” chemical without the “not dead yet” chemical, they drag away the body.
Understanding this behavior may help scientists figure out how to stop Argentine ants from invading new places and causing problems. Choe would like to find a way to use the newly discovered chemicals to spread ant killer to Argentine ant nests.
The ants’ removal behavior is important to the overall health of the nest. “Being able to quickly remove dead individuals and other possible sources of disease is extremely important to all animals living in societies, including us,” says Choe. “Think about all the effort and money that we invest daily in waste management.”
51. The underlined word “twist” in Paragraph 3 means _____.
A. an unexpected change                              B. a clear mistake
C. an important key                                        D. a shocking conclusion
52. Ants judge whether another one is dead or not depending on ______.
A. the sense of taste                                      B. the sense of smell
C. the sense of touch                                               D. the sense of sight
53. The result of the research can be used to ______.
A. kill troublesome pests
B. solve the problem of endangered species
C. prevent further expansion of the ants’ territory
D. keep the balance of nature
54. Why is it important to remove dead individuals?
A. Because it is easier to manage the living.
B. Because it can save money to deal with the waste.
C. Because it can provide more space for the living.
D. Because it can keep the living from suffering disease.
55. What might be the best title of the text?
A. Dead or living? It is easy to judge
B. Pulling away the dead ants is a difficult task
C. Ant nests have great undertaking capacity
D. Leaving it alone or taking it away? Ants feel puzzled

A nine-year-old kid was sitting at his desk when suddenly there was a puddle （/JC^C）between his feet and the front of his trousers was wet．He thought his heart was going to stop because he couldn't possibly imagine how this had happened．It had never happened before, and he knew that when the boys found out he would never hear the end of jt. When the girls found out, they would never speak to him again as long as he lived．

He prayed this prayer, "Dear God, I need help now! Five minutes from now I'm dead meat!" He looked up from his prayer and here came the teacher with a look in her eyes that said he had been discovered．As the teacher was walking toward him, a classmate named Susie was carrying a goldfish bowl full of water．Susie tripped （绊倒） in front of the teacher and dumped （倒） the bowl of water in the boy's lap．The boy pretended to be angry, but all the while was saying to himself, "Thank you．Lord!"

Now all of a sudden, instead of being the object of ridicule, the boy was the object of sympathy．The teacher rushed him downstairs and gave him gym shorts to put on while his trousers dried out．All the other children were on their hands and knees cleaning up around his desk．The sympathy was wonderful．But as life would have it, the ridicule that should have been his had been transferred （转移） to someone else—Susie．She tried to help, but they told her to get out．

When school was over, the boy walked over to Susie and whispered, "You did that on purpose, didn't you?" Susie whispered back, "I wet my trousers once, too!"

1.The underlined sentence in Paragraph 1 means ____        .

A．the boys would never play with him

B．the boys would treat him as usual

C. he would hardly hear any praise from the boys

D．he would be laughed at by the boys endlessly

2.After Susie dumped water in his lap, the boy was in a state of ___     

    A．excitement       B．relief          C．anxiety      D．anger

3.What did the other kids do after the incident?

A．They offered him dry clothes．       

B．They laughed at the boy rudely,

C．They helped the boy do the cleaning．   

D．They urged the boy to get out angrily,

4.Why did Susie dump water in the boy's lap?

A．The boy asked her to do so．        

B．She just did it by accident．

C．The teacher tripped her on purpose．        

D．She knew the boy's embarrassment．