ABCD请按实际情况填写。其他请参照下表填写。
A, B, C, D, E(AB), F(AC)
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A. Control of Respiration B. Basic tips for preserving cut flowers C. Role of Respiration D. Most Important Aspect of Flower Care E. Need for Clean Water F. Ways of Stopping Respiration |
1.
While everybody enjoys fresh cut flowers around his house, few people know how to keep them for as long as possible. This may be done by keeping in mind a few simple facts. The key to keeping fresh cut flowers for a week or more without floral preservatives(which contain biocides that kill bacteria and fungus) is to keep the water fresh and the stems free of air pockets so they can continue to draw up water.
2.
An important thing to remember about cut flowers is that they are sensitive to temperature. For example, studies have shown that cut carnations(康乃馨) retain their freshness eight times longer when kept at 12℃ than when kept at 26℃. Keeping freshly harvested flowers at the right temperatures is probably the most important aspect of flower care.
3.
Flowers are not intended by nature to live very long. Their biological purpose is simply to attract birds or insects, such as bees, for pollination (授粉). After that, they quickly dry up and die. The process by which flowers consume oxygen and produce carbon dioxide, called respiration (呼吸), generates the energy the flower needs to give the flower its shape and colour. The making of seeds also depends on this energy. While all living things respire, flowers have a high level of respiration. A result of all this respiration is heat, and for flowers the level of heat relative to the mass of the flower is very high. Respiration also brings about the eventual death of the flower. Thus the greater the level of respiration, the sooner the flower dies.
4.
How, then, to control the rate at which flowers die? By controlling respiration. How is respiration controlled? By controlling temperature. We know that respiration produces heat, but the reverse is also true. Thus by maintaining low temperatures, respiration is reduced and the cut flower will age more slowly.
5.
Another vital factor in keeping cut flowers is the quality of the water in which they are placed. Flowers find it difficult to “drink” water that is dirty or otherwise polluted. Even when water looks and smells clean, it almost certainly contains harmful substances that can endanger the flowers. To rid the water of these unwanted substances, household chlorine bleach (含氯漂白剂) can be used in small quantities. It is recommended that 15 drops of chlorine bleach(at 4% solution) be added to each litre of water. The water and solution should also be replaced each day.
LONDON—Life for Cathy Hagner and her three children is set to permanent(永久的) fast-forward.
Their full school day and her job as a lawyer's assistant are busy enough. But Hagner also has to take the two boys to soccer or hockey or basketball while dropping off her daughter at piano lessons or Girl Scout Club.
Often, the exhausted family doesn't get home until 7 pm. There is just time for a quick supper before homework. In today's world, middle-class American and British parents treat their children as if they are competitors racing for some finishing line.
Parents take their children from activity to activity in order to make their future bright. It seems that raising a genius has become a more important goal than raising a happy and well-balanced child.
"Doctors across the country are reporting a growing number of children suffering from stomachaches and headaches due to exhaustion and stress," says child expert William Doherty of the University of Minnesota.
Teachers are dealing with exhausted kids in the classroom. It's a very serious problem. Many children attend after-school clubs by necessity. But competitive pressures also create an explosion of activities. They include sports, language, music and math classes for children as young as four.
"There is a new parenting trend under way which says that you have to tap all your child's potential at a young age; otherwise you will let him down,” says Terry Alter, a Cambridge-based child and adolescent psychiatrist （青少年精神病专家）
"It isn't entirely new: there have always been pushy parents. But what was previously seen as strange behaviour is now well accepted."
1.From the second paragraph of this passage we can find that ______.
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A．Hagner wastes much time helping her children's lessons |
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B．Hagner doesn't spend much time on her full-time job |
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C．Hagner is interested in spots and music |
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D．Hagner busies herself by following a trend |
2.British parents, as the writer described in this passage, _____.
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A．treat their children as spots players |
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B．pay no attention to their children's lessons |
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C．bring up their children in a simple way |
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D．give their children little time to develop freely |
3.The writer's opinion about after-school clubs is that ______.
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A．activities in the country are too competitive |
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B．children should attend four clubs at a time |
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C．some clubs result in competitive pressures |
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D．clubs should have more subjects for school children |
4.The last paragraph tells us that in Britain ______.
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A．parents used to take their children to every club |
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B．parents used to be wise on how to raise children |
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C．parents have all benefited from children's clubs |
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D．parents have come to know the standard of education |
Have you ever wondered why the roots of the plants always know which way to grow—into the soil but not above it? Some British scientists have recently solved this mystery.
It turns out that roots have special hairs that tie them into the soil and help them grow their way past obstacles, a team at the John Inners Center in Norwich reports in the February 29 issue of Journal Science.
“The key is in the fuzzy(有绒毛的)coat of hairs on the roots of plants,” says professor Liam Dolan. “We have found a growth control system that enables these hairs to find their way and to become longer when their path is clear.”
Root hairs explore the soil in much the same way a person would feel their way in the dark. If they come across an obstacle, they make their way around until they can continue growing in an opening. In the meantime, the plant is held in place as the hairs grip(紧紧抓住)the soil.
The hairs are guided by a clever chemical trick. A protein(蛋白质) at the tip of the root hairs called RHD2 helps them to take calcium(钙) from the soil. Calcium makes the hairs grow, and produce more RHD2, and take more calcium.
But when an obstacle blocks the hair’s path, or the hair reaches the surface of the soil, the cycle is broken and growth starts in another direction.
This system gives plants the flexibility to explore a complex environment and to live in even the most unpromising soils, says Dolan.
In poor soils such as in parts of Australia and Africa, native plants have adapted by producing enormous numbers of root hairs. A better understanding of this adaptation will allow scientists to develop hairy rooted crops that can grow in unfriendly environments.
According to Dolan, “Research in the John Inners Center is taking a breeding approach to increase hair length in wheat but it will be some time before new cultivars(栽培变种) are developed.”
1.The passage is mainly about _______.
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A．why the roots of plants grow into the soil but not above it |
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B．how the roots of plants grow into the soil but not above it |
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C．the process of plants growth |
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D．a growth control system of plants |
2.How does the circle work?
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A．RHD2 takes calcium from the soil, which makes hairs grow, and produce RHD2 and take more calcium |
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B．Roots take RHD2 and calcium from the soil and produce RHD2 |
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C．Roots make hairs grow, and produce RHD2, and take more calcium |
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D．RHD2 takes protein, which makes hairs grow, and produce RHD2, and take more calcium |
3.We can infer from the last paragraph that ________.
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A．hairy rooted crops can grow better in unfriendly environments |
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B．a new cultivar of wheat with long hair has been developed by scientists |
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C．a new cultivar of wheat with long hair is still on test |
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D．the roots of plants always know which way to grow |
Five years ago, David Smith wore an expensive suit to work every day. “I was a clothes addict,” jokes. “I used to carry a fresh suit to work with me so I could change if my clothes got wrinkled.” Today David wears casual clothes---khaki pants and sports shirt---to the office. He hardly ever wears necktie. “I’m working harder than ever,” David says, “and I need to feel comfortable.”
More and more companies are allowing their office workers to wear casual clothes to work in the United States. The change from formal to casual office wear has been gradual. In the early 1990s, many companies allowed their employees to wear casual clothes on Friday (but only on Friday). This became known as “dress-down Friday” or “casual Friday.” “What started out as an extra one-day-a-week benefit for employees has really become an everyday thing,” said business consultant Maisly Jones.
Why have so many companies started allowing their employees to wear casual clothes? One reason is that it’s easier for a company to attract new employees if it has a casual dress code. “A lot of young people don’t want to dress up for work,” says the owner of a software company, “so it’s hard to hire people if you have a conservative dress code.” Another reason is that people seem happier and more productive when they are wearing comfortable clothes. In a study conducted by Levi Strauss and Company, 85 percent of employers said that they believe that casual dress improves employee morale. Only 4 percent of employers said that casual dress has a negative impact on productive. Supporters of casual office wear also argue that a casual dress code helps them save money. “Suits are expensive, if you have to wear one every day,” one person said. “For the same amount of money, you can buy a lot more casual clothes.”
1.David Smith refers to himself as having been “a clothes addict” because_______.
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A．he often wore khaki pants and a sports shirt |
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B．he couldn’t stand a clean appearance |
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C．he wanted his clothes to look neat all the time |
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D．he didn’t want to spend much money on clothes |
2.David Smith wears casual clothes now, because________
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A．they make him feel at ease when working |
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B．he cannot afford to buy expensive clothes |
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C．he looks handsome in casual clothes |
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D．he no longer works for any company |
3.According to this passage, which of the following statements is FALSE?
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A．Many employees don’t like a conservative dress code. |
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B．Comfortable clothes make employees more productive |
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C．A casual clothes code is welcomed by young employees |
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D．All the employers in the U.S are for casual office wear. |
4.In this passage, the following advantages of casual office wear are mentioned EXCEPT_______.
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A．saving employees’ money |
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B．making employees more attractive |
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C．improving employees’ motivation |
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D．making employees happier |
There are many ways to keep kids of all ages physically fit besides sports.
If your child is a natural athlete or ___1____ lover, he or she is probably already active and __2___ easy to get moving. But if, like me, you are the parent of a junior sofa potato, complete with a(n) __3____ controller in one hand and a bag of potato chips in the other, you know what it is like to have your ___4__ to go outside to play met with, at best, silence or at worst, cry and ___5___.
If logic, threats and lectures on health don’t work, turn to __6___: trick him or her into liking by making it into fun. __7____ enjoyment, not pressure or physical fitness or anything that seems to be “good for you”. That is where the dancing and nature walks ___8____. Health experts say that the answer to the question, “Which type of exercise is best for my child?” is “Whichever one he or she likes best.” It doesn’t have to be swimming or soccer or gymnastics. ____9___ play, especially with the rest of the family, will ___10___ the body’s requirements for regular aerobic movement (有氧运动) just well, and won’t ever seem like exercising.
___11____, if nature is an interest, walk vigorously around finding every leaf, insect, and _12___ print in the park. If rock radio is the station of choice, ___13____ to the music. Get the family members playing catch, touch football together. Organize a(n) __14____ science group to walk around your neighborhood and pick your rubbish. Make every trip to the pool an excuse for playing games in the water together.
Remember that the goal is to set a pattern for lifelong fitness. And if you don’t make it _15___, kids are never going to keep it up.
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If I hadn’t stood under the ladder to catch you when you fell, you _____ now.
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A．didn’t smile |
B．won’t smile |
C．wouldn’t be smiling |
D．couldn’t have smiled. |
