If a diver surfaces too quickly, he may suffer the bends. Nitrogen(氮) dissolved(溶解) in his blood is suddenly liberated by the reduction of pressure. The consequence, if the bubbles (气泡)accumulate in a joint, is sharp pain and a bent body—thus the name. If the bubbles form in his lungs or his brain, the consequence can be death.
Other air-breathing animals also suffer this decompression(减压) sickness if they surface too fast: whales, for example. And so, long ago, did ichthyosaurs. That these ancient sea animals got the bends can be seen from their bones. If bubbles of nitrogen form inside the bone they can cut off its blood supply. This kills the cells in the bone, and consequently weakens it, sometimes to the point of collapse. Fossil (化石)bones that have caved in on them selves are thus a sign that the animal once had the bends.
Bruce Rothschild of the University of Kansas knew all this when he began a study of ichthyosaur bones to find out how widespread the problem was in the past. What he particularly wanted to investigate was how ichthyosaurs adapted to the problem of decompression over the 150 million years. To this end, he and his colleagues traveled the world’s natural-history museums, looking at hundreds of ichthyosaurs from the Triassic period and from the later Jurassic and Cretaceous periods.
When he started, he assumed that signs of the bends would be rarer in younger fossils, reflecting their gradual evolution of measures to deal with decompression. Instead, he was astonished to discover the opposite. More than 15% of Jurassic and Cretaceous ichthyosaurs had suffered the bends before they died, but not a single Triassic specimen(标本) showed evidence of that sort of injury.
If ichthyosaurs did evolve an anti-decompression means, they clearly did so quickly—and, most strangely, they lost it afterwards. But that is not what Dr Rothschild thinks happened. He suspects it was evolution in other animals that caused the change.
Whales that suffer the bends often do so because they have surfaced to escape a predator (捕食动物) such as a large shark. One of the features of Jurassic oceans was an abundance of large sharks and crocodiles, both of which were fond of ichthyosaur lunches. Triassic oceans, by contrast, were mercifully shark- and crocodile-free. In the Triassic, then, ichthyosaurs were top of the food chain. In the Jurassic and Cretaceous, they were prey(猎物) as well as predator—and often had to make a speedy exit as a result.
1.Which of the following is a typical symptom of the bends?
A. A twisted body. B. A gradual decrease in blood supply.
C. A sudden release of nitrogen in blood. D. A drop in blood pressure.
2.The purpose of Rothschild’s study is to see________ .
A. how often ichthyosaurs caught the bends B. how ichthyosaurs adapted to decompression
C. why ichthyosaurs bent their bodies D. when ichthyosaurs broke their bones
3.Rothschild’sfindingstatedinParagraph4 .
A. confirmed his assumption B. speeded up his research process
C. disagreed with his assumption D. changed his research objectives
4.Rothschild might have concluded that ichthyosaurs.
A. failed to evolve an anti decompression means
B. gradually developed measures against the bends
C. died out because of large sharks and crocodiles
D. evolved an anti decompression means but soon lost it
Why College Is Not Home
The college years are supposed to be a time for important growth in autonomy(自主性) and the development of adult identity. However, now they are becoming an extended period of adolescence, during which many of today’s students are not shouldered with adult responsibilities.
For previous generations, college was a decisive break from parental control; guidance and support needed to come from people of the same age and from within. In the past two decades, however, continued connection with and dependence on family, thanks to cell phones, email and social media, have increased significantly. Some parents go so far as to help with coursework. Instead of promoting the idea of college as a passage from the shelter of the family to autonomy and adult responsibility, universities have given in to the idea that they should provide the same environment as that of the home.
To prepare for increased autonomy and responsibility, college needs to be a time of exploration and experimentation. This process involves ＂trying on＂ new ways of thinking about oneself both intellectually(在思维方面)and personally. While we should provide ＂safe spaces＂ within colleges, we must also make it safe to express opinions and challenge majority views. Intellectual growth and flexibility are fostered by strict debate and questioning.
Learning to deal with the social world is equally important. Because a college community(群体) differs from the family, many students will struggle to find a sense of belonging. If students rely on administrators to regulate their social behavior and thinking pattern, they are not facing the challenge of finding an identity within a larger and complex community.
Moreover, the tendency for universities to monitor and shape student behavior runs up against another characteristic of young adults: the response to being controlled by their elders. If acceptable social behavior is too strictly defined(规定) and controlled, the insensitive or aggressive behavior that administrators are seeking to minimize may actually be encouraged.
It is not surprising that young people are likely to burst out, particularly when there are reasons to do so. Our generation once joined hands and stood firm at times of national emergency. What is lacking today is the conflict between adolescents’ desire for autonomy and their understanding of an unsafe world. Therefore, there is the desire for their dorms to be replacement homes and not places to experience intellectual growth.
Every college discussion about community values, social climate and behavior should include recognition of the developmental importance of student autonomy and self-regulation, of the necessary tension between safety and self-discovery.
1.What’s the author’s attitude toward continued parental guidance to college students?
A. Sympathetic. B. Disapproving.
C. Supportive. D. Neutral.
2.The underlined word ＂passage＂ in Paragraph 2 means___________.
A. change B. choice
C. text D. extension
3.According to the author, what role should college play?
A. To develop a shared identity among students.
B. To define and regulate students’ social behavior.
C. To provide a safe world without tension for students.
D. To foster students’ intellectual and personal development.
4.Which of the following shows the development of ideas in the passage?
A. 
B. 
C. 
D. 
|
“In the past going to the dentist wasn't always easy; but today it IS! New dental technologies like air abrasion(研磨) mean up to 80% of patients don't even need a shot! Other stateoftheart advancements make your treatment completely comfortable. Call me if you want gentle, affordable dental care.” —Dr John B. Gentle |
Total Family Care
Tomorrow's Dentistry Today
Cosmetics(美容) for Your Best Smile
Conveniences 24 hour emergency treatment Cable TV in every room Free second opinion Prepayment discounts Interest free financingInsurance accepted Credit cards and online pay accepted Call now for your free inmouth camera examination:
|
1.Who might be most interested in this advertisement?
A. Those who want to receive tooth treatment.
B. Those who want to become dentists.
C. Those who want to sell tooth medical equipment.
D. Those who want to write an article on tooth care.
2.According to the advertisement, those who may go to the dentist's are probably attracted by ________.
A. free emergency treatment B. cheapest naturallooking cosmetics
C. new dental technologies D. discounted inmouth camera examination
Until a few years ago, I was a calm person. If you were going to ______ me I almost never lost it ______； of course I felt hurt, but I didn't show it.
Then, one day, I met my husband and I fell ______ in love with him, a proud Italian who loudly discusses things ______ with himself when he's not happy. Things got worse for me when we started ______ on things. He seemed really angry and loud, while I seemed detached and polite. Truth is that I was ______ too. Fight after fight, he always acted as if nothing had happened a few minutes after each quarrel, while my moments of ______ discontent started to ______ more and more in time until they became hours, sometimes even days.
I felt this had to change and the conversation went ______ like this:
Me: “Either you change your ______ when we fight or I will start avoiding any discussion, and this will ______ our relationship.”
Him: “Did you ______ the Mpemba Effect? If you put two ______ containers filled with the same amount of water into the fridge except that one has boiling water in it while the other one has water at ambient(周围的)______， the boiling water will ______ faster than the ambient water. Baby, you got to boil first, to cool down faster. That's why the Italians live ______ than Canadians.”
The connection he suggested is to be ______. but I have learned a fact I didn't know, one that has ______ me to understand that if I'm angry about something or someone, for that anger to disappear, it has to be towards the ______ or otherwise it is like hiding the dust under the ______: your house might look clean, but it is not.
1.A. cheat B. offend C. impress D. defend
2.A. in return B. in place C. in public D. in time
3.A. hopelessly B. steadily C. hurriedly D. blindly
4.A. always B. ever C. even D. seldom
5.A. working B. disagreeing C. operating D. trying
6.A. boiling B. struggling C. controlling D. preparing
7.A. possible B. abrupt C. extra D. inner
8.A. spread B. withdraw C. recover D. expand
9.A. more or less B. sooner or later C. by and by D. up and down
10.A. vision B. viewpoint C. attitude D. attention
11.A. compensate B. sacrifice C. mend D. clarify
12.A. hear about B. worry about C. learn from D. hear from
13.A. mobile B. relevant C. solid D. similar
14.A. level B. temperature C. heat D. environment
15.A. burst B. deposit C. explode D. freeze
16.A. longer B. shorter C. wealthier D. simpler
17.A. practiced B. proven C. inspected D. created
18.A. informed B. reminded C. inspired D. required
19.A. outside B. inside C. public D. personal
20.A. dustpan B. broom C. roof D. carpet
—Won’t Terry be upset?
—_______? He never thinks about anyone but himself.
A. Guess what B. Now what
C. Who cares D. Who knows
Only since the Industrial Revolution ________ in places away from their homes or been left to raise small children without the help of multiple adults.
A. most people have worked B. have most people worked
C. most people had worked D. had most people worked
