Below is a selection from a popular science book.
If blood is red, why are veins (静脉) blue?
Actually, veins are not blue at all. They are more of a clear, yellowish color. Although blood looks red when it’s outside the body, when it’s sitting in a vein near the surface of the skin, it’s more of a dark reddish purple color. At the right depth, these blood-filled veins reflect less red light than the surrounding skin, making them look blue by comparison.
Which works harder, your heart or your brain?
That kind of depends on whether you’re busy thinking or busy exercising. Your heart works up to three times harder during exercise, and shifts enough blood over a lifetime to fill a supertanker. But, in the long run, your brain probably tips it, because even when you’re sitting still your brain is using twice as much energy as your heart, and it takes four to five times as much blood to feed it.
Why do teeth fall out, and why don’t they grow back in grown-ups?
Baby (or “milk”) teeth do not last long; they fall out to make bigger room for bigger, stronger adult teeth later on. Adult teeth fall out when they become damaged, decayed and infected by bacteria. Once this second set of teeth has grown in, you’re done. When they’re gone, they are gone. This is because nature figures you’re set for life, and what controls regrowth of your teeth switches off.
Do old people shrink as they age?
Yes and no. Many people do get shorter as they age. But, when they do, it isn’t because they’re shrinking all over. They simply lose height as their spine (脊柱) becomes shorter and more curved due to disuse and the effect of gravity (重力). Many (but not all) men and women do lose height as they get older. Men lose an average of 3-4 cm in height as they age, while women may lose 5 cm or more. If you live to be 200 years old, would you keep shrinking till you were, like 60 cm tall, like a little boy again? No, because old people don’t really shrink! It is not that they are growing backwards—their legs, arms and backbones getting shorter. When they do get shorter, it’s because the spine has shortened a little. Or, more often, become more bent and curved.
Why does spinning make you dizzy (眩晕的)?
Because your brain gets confused between what you’re seeing and what you’re feeling. The brain senses that you’re spinning using special gravity-and-motion-sensing organs in your inner ear, which work together with your eyes to keep your vision balance stable. But when you suddenly stop spinning the system goes out of control, and your brain thinks you’re moving while you’re not!
Where do feelings and emotions come from?
Mostly from an ancient part of the brain called the limbic system. All mammals （哺乳动物）have this brain area — from mice to dogs, cats, and humans. So all mammals feel basic emotions like fear, pain and pleasure. But since human feelings also involve other, newer bits of the brain, we feel more complex emotions than any other animal on the planet.
If exercise wears you out, how can it be good for you?
Because our bodies adapt to everything we do to them. And as far as your body is concerned, it’s “use it, or lose it”! It’s not that exercise makes you healthy; it’s more that a lack of exercise leaves your body weak and easily affected by disease.
1.What is the color of blood in a vein near the surface of the skin?
A. Blue B. Light yellow
C. Red D. Dark reddish purple
2.Why do some old people look a little shrunken as they age?
A. Because their spine is in active use.
B. Because they are more easily affected by gravity.
C. Because they keep growing backwards.
D. Because their spine becomes more bent.
3.Which of the following statements about our brain is true?
A. In the long run, our brain probably works harder than our heart
B. When our brain senses the spinning, we will feel dizzy.
C. The brains of the other mammals are as complex as those of humans.
D. Our feelings and emotions come from the most developed area in our brain.
Imagination and fantasy can play an important role in achieving the things we fear. Children know this very well. Fred Epstein, in his book I Make It to Five, tells a story he heard from one of his friends about Tom, a four-year-old boy with a cancer in his back bone. He came through several operations and a lot of pain by mastering his imagination.
Tom loved to pretend, and he particularly loved to play superheroes. Dr. Epstein explained that it was actually a brilliant way for his young mind to handle the terrifying and painful life he led.
The day before his third trip to the operating room, Tom was terribly afraid. “Maybe I could go as Superman,” he whispered to his mom. Hearing this, the mother hesitated for a while. She has avoided buying the expensive costume(戏装), but finally she agreed.
The next day Tom appeared as the powerful Superman, showing off through the hospital halls and coolly waving his hand to the people greeting him along the way. And Tom, with the strength of his fantasy, successfully made it through the operation.
The power of imagination need not be reserved for children only. We all have the power to use our fantasies to attempt things we never thought possible, to go through those things that seem impossible, and to achieve what we never believed we could. Just as Dr. Epstein puts it, “If you can dream it, you can do it.”
It doesn’t mean that you should dress as a superhero for your next job interview. But, next time you are tested in a way that seems impossible, imagine what it would take to overcome it. Become the person you need to become to win over your challenge and do it in your mind first. So, let your imagination run wild, and dare to dream.
1.What do we know about Tom?
A. He was seriously ill.
B. He was a dishonest boy.
C. He was crazy about magic.
D. He was Dr. Epstein’s patient.
2.What can be inferred about Tom’s mother?
A. She was a rich lady.
B. She refused Tom’s request.
C. She wanted Tom to be a superhero.
D. She wanted to get Tom through the pain.
3.When Tom went for the third operation, he_________.
A. pretended to be painful B. acted like a superhero
C. appeared in poor spirits D. argued with his mother
4.In the last paragraph, you are advised________.
A. to go through some difficult tests
B. to wake up from your wild dreams
C. to become a powerful person in your mind
D. to wear expensive clothes for job interviews
阅读下面短文，掌握其大意，然后从各题所给出的A、B、C、D四个选项中选出最佳选项，并在答题卡上将该项涂黑。
As I held my father’s hands one night, I couldn’t help but notice their calluses(老茧）and roughness. His hands tell the story of his life as a 31 , including all his struggles.
One summer, I remember, a drought (旱灾）hit Ontario, turning it into a 32 desert. On one of those hot mornings I was picking sweet corn with my dad to fill the last 33 from the grocery store. Fifty dozen was all we needed, which 34 took twenty minutes. That morning, however, the process didn’t 35 quickly. After forty minutes of aimlessly walking in the field, we 36 needed twenty dozen. I was completely frustrated and 37 . Dropping the basket heavily, I declared, “If the store wants its last twenty dozen, they can pick it themselves.” Dad 38 , “Just think, my little girl, only ten dozen left for each of us and then we’re 39 .” Such is Dad—whatever problem he 40 , he never gives up.
41 , the disastrous (灾难性的) effects of the drought were felt all over our county. It was a challenging time for everyone, 42 Dad remained optimistic. He 43 to be grateful for other things like good health and food on our plates. Only then did I truly begin to 44 Dad and his faith that guided us through the hard times.
Dad is also a living example of real 45 . From dawn to dusk, he works countless hours to 46 our family. He always puts our happiness 47 his own, and never fails to cheer me on at my sports games 48 his exhaustion after long days. His loving and selfless nature has inspired me to become more sympathetic (同情心的) and 49 putting others first.
Dad, the life 50 I have learned from you will stay with me forever. You are my father, teacher, friend and, most importantly, my hero.
1.A. teacher B. gardener C. farmer D. grocer
2.A. stormy B. lively C. disappearing D. burning
3.A. order B. form C. gap D. position
4.A. repeatedly B. normally C. finally D. really
5.A. go B. begin C. occur D. change
6.A. yet B. still C. even D. nearly
7.A. surprised B. nervous C. angry D. frightened
8.A. apologized B. cried C. complained D. laughed
9.A. lost B. done C. gone D. touched
10.A. meets with B. brings up C. works out D. thinks about
11.A. Thankfully B. Hopefully C. Unfortunately D. Strangely
12.A. or B. for C. so D. but
13.A. happened B. seemed C. continued D. aimed
14.A. face B. appreciate C. examine D. question
15.A. love B. pride C. friendship D. honesty
16.A. support B. settle C. start D. impress
17.A. after B. before C. beside D. under
18.A. in spite of B. in terms of C. in control of D. in place of
19.A. careful B. regretful C. considerate D. humorous
20.A. history B. motto C. patterns D. lessons
—How often do you call your parents?
—______, but usually once a week.
A. Forget it B. Once in a while
C. It depends D. I’ve no idea
The young man thought carefully for several days and decided to ______ the job offer.
A. lift up B. take up C. sweep up D. set up
The traffic rule says young children under the age of four and ______ less than 40 pounds must be in a child safety seat.
A. being weighed B. to weigh C. weighing D. weighed
