题目
题型:不详难度:来源:
Plant and animals often use color to attract attention. The substances responsible for these colors belong to a class of chemical called antioxidants(抗氧化物). Plants make antioxidant to protect themselves from the sun’s ultraviolet(UV)(紫外线)light.
Ultraviolet light causes chemicals called free radicals(自由基)to form within plant cells. They can destroy parts of plant. Free radicals also have damaging effects on human beings. Some of these effects like wrinkled skin can be seen. The damage is caused by the free radicals attacking cells in our bodies. Certain cancers and heart disease are linked to free radicals.
Our bodies have natural defences for fighting off free radicals. While we are young, our defences are pretty strong. However, they get weaker as we get older. The body’s built-in defences can only go so far without extra help.
The key to fighting free radicals with fruits and vegetables is to mix and match colors. It’s like sunscreen(防晒霜)for the inside of your body. Go for a range of very bright colors. Colorful foods contain hundreds of healthy chemicals not found anywhere else.
Research into how chemicals in blueberries affect the brain’s function in rats suggests that these chemicals may help our own brains work more efficiently.
Don’t just blame the sun. Ultraviolet light isn’t the only source of free radicals. If you breathe polluted air such as smog, automobile exhaust(废气), or wasted gas from a factory, you take in chemicals that also cause such damage. And, the body itself produces free radicals as it processes food.
小题1:Which of the following not true?
A.Antioxidants are responsible for plant colors |
B.Plants use color to attract attention |
C.Antioxidants can protect plants from UV light |
D.Antioxidants help free radicals to attack plants |
a Wrinkled skin can be seen
b UV light causes free radicals to form
c Free radicals damage cells in our bodies
d The sun gives out UV light
A.a,b,c,d | B.d,b,c,a |
C.c,a,d,b | D.d,b,a,c |
A.our bodies’ defences are not natural |
B.we are too young to defend ourselves |
C.our defences get weaker as we get older |
D.our bodies’ built-in defences can only go away |
A.Colorful food | B.UV light from the sun |
C.Polluted air | D.The body itself |
答案
小题1:D
小题2:B
小题3:C
小题4:A
解析
试题分析:这篇文章讲述了太阳的紫外线、烟雾、汽车的排气、工厂的废气等都可造成自由基的生成,自由基会破坏人体细胞,各种颜色的食物是帮助我们抗自由基的有效方法。
小题1:根据Plant and animals often use color to attract attention. The substances responsible for these colors belong to a class of chemical called antioxidants(抗氧化物). Plants make antioxidant to protect themselves from the sun’s ultraviolet(UV)(紫外线)light.排除A、B和C,故选D。
小题2:事情发生的先后顺序是:先是太阳释放出紫外线,然后紫外线造成自由基的生成,接着自由基破坏我们身体的细胞,最后皮肤起皱纹,故选B。
小题3:根据However, they get weaker as we get older. The body’s built-in defences can only go so far without extra help.所以答案为C。
小题4:各种颜色的食物是帮助我们抗自由基的,因此选A。
点评:要想答好题目,重在理解全文意思。这篇文章比较难,先看问题,再带着问题读短文,找出各段落的主旨句,理解全文内容,总结全文中心,然后再回到问题上来,很容易选出正确答案。
核心考点
试题【Nature is full of color, from rainbows and roses to butterfly wings and peacock 】;主要考察你对题材分类等知识点的理解。[详细]
举一反三
It’s not news that we spend more time than ever texting and online.1 Yes, that’s right: a 2010 study shows that more teens are reading good old-fashioned, ink-on-paper books.
Reading is a good way to discover the next big thing and to learn a little more about yourself while you’re at it.2 Here are some tips.
Start with your interests
Reading on your own isn’t like reading for school. You can pick something that’s all about your interests, whether it’s ancient martial arts, computers, or fashion design.
Reading the blurbs(简介)
The reviews and quotes on the back and inside covers of many books are called “blurbs”. 3if you find a book you really like, take a minute to read the quotes(if there are any) and see which authors praised the book. Often, they’ll have similar styles and you might find you like books by those authors too.
Ask an expert
4 Explain your interests--- rock stars, sports teams, historical events, humors, whatever you’re into—and any writers you like, and your librarian can point you toward books that you’ll love.
Finally, you’ll probably enjoy what you’re reading a lot more if you find a quiet place and make time for the book.5 You can put on some good music(ideally without lyrics), get yourself some tea and a comfy spot, and let yourself be carried away by the book.
You’ll see that time does fly when you are reading something you love!
A.Join a group with your friends and people you trust. |
B.But do you know how to pick a book you’ll really like? |
C.But did you know that we also spend more time reading? |
D.Your local library can hook you up with a whole lot of great book ideas. |
F. We all multitask, but most reading is best enjoyed when you can concentrate and focus on it.
G. They give you an idea of what the book is about, and can also help you pick future books too.
The research has found that teenagers’ brains continue developing far longer into adulthood than we used to think. Teens may look like young adults but their brain structure is similar to that of much younger children.
“It is not always easy for teens to pay attention in class without letting their minds wander, or to ignore distractions from their younger brothers or sisters when trying to solve a maths problem,” said Dr Iroise Dumon-theil. “But it’s not the fault of teenagers that they can’t pay attention and are easily distracted. It’s to do with the structure of their brains. Teens simply can’t think as well as an adult.”
The research showed that the brain of a teenager works less effectively than that of an adult. “We knew that the front of the brain of teens functioned in a chaotic (混乱的) way but we didn’ t realize it continued until the late 20s or early 30s,” said Dr Sarah-Jayne Blakemore, who led the research.
Chaotic thought patterns are a result of teenagers’ brains containing too much grey matter — the cell bodies and connections which carry messages within the brain. As we age, the amount of grey matter in our brain reduces.
“What our research has shown is that there is simply too much going on in the brains of teens,” said Blakemore. “The result is that their brain energy and resources are wasted and their decision-making process is badly influenced. Adults, on the other hand, have less grey matter. This means that the brain works far more effectively.”
小题1:The underlined word “solace” in Paragraph 1 may mean _____.
A. notice | B.medicine | C.comfort | D.action |
A.teens’ brains continue to do much needless work |
B.the grey matter in young children’s front brain becomes active |
C.people are not likely to be distracted until their late 30s |
D.adults are more independent than teens |
A.It makes us always feel disappointed. |
B.It makes us more intelligent. |
C.It had a bad effect on the growth of teens. |
D.It had a bad effect on decision-making. |
A.Teens have different brains from those of children. |
B.Adults work more effectively than teens. |
C.Grey matter makes teens unable to pay attention. |
D.Brain energy is wasted in the brain’s activity. |
It is always more important to know how to study by oneself than to memorize some facts or a formula(公式). It is actually quite easy to learn a certain fact in history or a formula in mathematics. But it is very difficult to use a formula in working out a math problem. Great scientists before us didn’t get everything from school .Their teachers only showed them the way. Edison did not even finish primary school. But they were all so successful. They invented so many things for mankind. The reason for their success is that they knew how to study. They read books that were not taught at school . They would ask many questions as they read. They did thousands of experiments. They worked hard all their lives, wasting not a single moment. Above all , they knew how to use their brain.
小题1: To work out a math problem, you need to know __________.
A.only a certain formula |
B.how to memorize some facts |
C.only some facts |
D.the method to work it out |
A.They received good education. |
B.They were very clever. |
C.They knew how to learn. |
D.They learned lots of facts and formulas. |
A.They read a lot of books and asked many questions while reading. |
B.They did thousands of experiments. |
C.They always worked hard and never wasted time. |
D.All of the above. |
小题1: Annealing can make metal _______________.
A.hard and tough (韧) | B.hard but brittle |
C.soft but tough | D.soft and brittle |
A.To make it hard | B.To make it soft |
C.To make it cool | D.To make it brittle |
A.It can be heated and then cooled quickly |
B.It can be cooled and then heated slowly |
C.It can be heated and then cooled slowly |
D.It can be cooled and then heated quickly |
Teachers who are anxious to defend their professional dignity have tried to put the blame on the students. They mentioned their right to privacy 隐私)and for this reason they requested the Ministry of Education (MOE) to prohibit PDAs in schools. On the other hand, some parents and students have taken a different position. They feel that the teacher is also at fault. Caught up in the war of words between both sides, people are no longer interested in the “truth” of the matter which seems now unimportant. It was left to newspapers to discover the central point of the controversial issue, by stressing the problems that are not always easily noticed in our educational system.
For those responsible for educating the young, this PDA incident conveys the message that “Times have changed”,a reality that must have been felt even more strongly by the female teacher when reflecting on this unpleasant experience. Different times call for different professional approaches in education. The ability to understand the students they are teaching has always been the quality of successful teachers. Despite some factors, the incident shows that the teacher lacks good qualities on her part. Besides, the rules under current system to deal with recalcitrant students need to be improved. Also, it is an example which shows the issue we are familiar with: what to do with new technology? With PDA, the new technology, the interaction (交流)between the teacher and students in classroom has been changed.
小题1:The author’s purpose in writing this passage is to______.
A.improve the teachers’ way of teaching |
B.stress the using of PDA in the classroom |
C.change the students’ behavior in the classroom |
D.discuss the potential problems of educational system |
A.difficult to control | B.interested in nothing |
C.unwilling to learn | D.ready to obey rules |
A.optimistic | B.critical |
C.uncertain | D.approval |
A.Whom to blame? |
B.The PDA incident |
C.Times have changed |
D.What to do with new technology? |
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