题目
题型：模拟题难度：来源：
blood makes as it flows through the heart. It sounds sort of like the noise of flowing water. This sound is
called a murmur.
Just like kids, murmurs have grades. Grade l is the softest-sounding murmur, and Grade 6 is the loudest.
A murmur graded 4, 5, or 6 is so loud you can actually feel a rumbling from it under the skin if you put your
hand on the person"s chest.
Most murmurs don"t mean anything is wrong. Doctors may call these "innocent", "functional", or "normal"
murmurs.
One common type of normal murmur is Still"s murmur, named for the doctor who first described it. This
murmur is most often heard in healthy children aged 3 to 7.
A normal murmur can get louder when the blood flows faster through the heart, like when kids have a
fever or run around. That"s because an increase in body temperature or activity makes the heart pump more
blood. When your temperature goes down, the murmur may get quieter or even disappear.
It can be easier to hear heart murmurs in kids because they have less fat, muscle, and bone between the
murmur and the doctor"s stethoscope (听诊器). Many normal murmurs become harder to hear as children
grow older, and some eventually disappear.
Even though most murmurs do not mean anything is wrong, sometimes a heart problem can cause a
murmur. If your doctor thinks your heart murmur could be due to a heart problem, you will need to see a
pediatric cardiologist. This kind of doctor knows a lot about children"s hearts.
B. Heart murmurs.
C. Murmur types.
D. Murmur grades.
B. listened to some light music
C. played football for two hours
D. finished reading a storybook
B. an experiment report
C. a hospital introduction
D. a medical advertisement
B. some heart murmurs can cause heart problems
C. doctors know what has led to low temperatures
D. a certain heart problem can cause a heart murmur
答案
核心考点
试题【阅读理解。 You know the sound of your heartbeat: lub-dub, lub-dub. In some people】；主要考察你对题材分类等知识点的理解。[详细]
举一反三
make our rivers fishless and our gardens and woodlands silent and birdless. Man, however much he may like
to pretend the opposite, is part of nature. Can he escape a pollution that is now so thoroughly spread
throughout our world?
We know that even single exposure to these chemicals, if the amount is large enough, can cause extremely
severe poisoning. But this is not the major problem. The sudden illness or death of farmers, farm workers and
others exposed to enough quantities of pesticides is very sad and should not happen. For the population as a
whole, we must pay more attention to the delayed effects of taking in small amounts of the pesticides that
unseeably pollute our world.
Responsible public health officials have pointed out that the biological effects of chemicals are increasing in
amount over long periods of time, and that the danger to the man may depend on the amount of the exposures
received throughout his lifetime. For these very reasons people easily take no notice of the danger. It is human
nature to shake off what may seem to us a future disaster. "Men are naturally most impressed by diseases
which have obvious signs," says a wise physician, Dr. Rene Dubos, "yet some of their worst enemies slowly
come near them unnoticed."
B. Possibly man will escape the effects of environmental pollution.
C. Pesticide-caused pollution may also kill people.
D. Man acts as if he did not belong to nature.
B. the present is more important to them than the future
C. humans are able to bear small amounts of poisoning
D. the danger does not become seen clearly and immediately
B. Birds are less sensitive to pesticides than humans.
C. The effects of pesticides on humans do not last as long as on fish.
D. Taking in small amounts of pesticides will not cause serious results.
B. people fail to notice hidden dangers caused by pesticides
C. diseases with obvious signs are mostly easy to cure
D. attacks by hidden enemies are likely to be deadly
by 12 years, sobering new research suggests.
The findings are from study that tracked nearly 5 000 British adults for 20 years, and they highlight yet
another reason to adopt a healthier lifestyle.
Overall, 300 people studied had all four unhealthy behaviors. Among them, 90 died during the study, or
30 percent. Among the 400 healthiest people with none of the four habits, 8 percent of them died.
The risk behaviors were., smoking tobacco; drowning more than three alcoholic drinks per day for men
and more than two daily for women; getting less than two hours of physical activity per week; and eating
fruits and vegetables fewer than three times daily.
These habits combined substantially increased the risk of death and made people who engaged in them
seem 12 years older than people in the healthiest group, said lead researcher Elisabeth Kvaavik of the
University of Oslo.
The healthiest group included never-smokers and those who had quit; women who had fewer than two
drinks daily and men who had fewer than three; those who got at least two hours of physical activity weekly;
and those who ate fruits and vegetables at least three times daily.
"You don"t need to be extreme" to be in the healthy category, Kvaavik said. "These behaviors add up, so
together it"s quite good. It should be possible for most people to manage to do it."
The US government generally recommends at least 4 cups of fruits or vegetables daily for adults,
depending on age and activity level, and about 2 hours of exercise weekly.
B. You would feel tired, lack of energy.
C. You may look older than you really are.
D. You may face the risk of death of cancer.
B. 24.
C. 56.
D. 120.
B. The results of four bad life habits.
C. The findings of a new research.
D. The recommends from the US government.
would help deal with climate change," the world"s leading authority on global warming has told The Observer.
Dr Rajendra Pachauri, chair of the United Nations Intergovernmental Panel on Climate Change, said that
people should then go on to reduce their meat consumption even further.
Pachauri, who was re-elected the panel"s chairman for a second six-year term last week, said diet change
was important because of the huge greenhouse gas emissions (排放) and other environmental problems
associated with raising cattle and other animals. "It was relatively easy to change eating habits compared to
changing means of transport," he said.
The UN"s Food and Agriculture Organisation has estimated that meat production ac counts for nearly a
fifth of global greenhouse gas emissions. These are produced during the production. For example, ruminants
(反刍动物), particularly cows, emit a gas called methane, which is 23 times more effective as a global
warming agent than give off CO2.
Pachauri can expect some opposite responses from the food industry to his advice, though last night he
was given unexpected support by Masterchef presenter and restaurateur John Torode. "I have a little bit and
enjoy it," said Torode. "Too much for any person is bad. But there"s a bigger issue here: where the meat
comes from. If we all bought British and stopped buying imported food, we"d save a huge amount of carbon
emissions."
Professor Robert Watson, the chief scientific adviser for the Department for Environment Food and Rural
Affairs, said government could help educate people about the benefits of eating less meat, but it should not
regulate. "Eating less meat would help, there"s no question about that," Watson said.
However, Chris Lamb, head of marketing for pig industry group BPEX, said the meat industry had been
unfairly targeted and was working hard to find out which activities had the biggest environmental impact and
reduce them. "Some ideas were contradictory," he said. "For example, one solution to emissions from cattle
and other animals was to keep them indoors, but this would damage animal welfare. Climate change is a very
young science and our view is ther are a lot of simple solutions being proposed."
B. Growth of cattle.
C. Methane from ruminants.
D. Processing of meat.
B. John Torode.
C. Robert Watson.
D. Chris Lamb.
B. ruminants should not be left outdoors
C. the meat industry will soon close down
D. we must do our duty to save the earth
B. More animals, more greenhouse gas
C. Less imported food, better our environment
D. Greater diet change, smaller climate change
注意：每个空格只填1个单词。
In 1829, U.S. farmers grew soybeans (大豆) for the first time. In the late 1800s, lots of farmers began
to grow soybeans as food for cattle. In 1904, at the Tuskegee Institute in Alabama, George Washington
Carver began studying the soybean. His discoveries changed the way people thought about the soybean. No
longer was it just a crop for cattle； it provided valuable protein and oil. Now soybean oil is the most popular
source for an alternative fuel.
Fueling diesel (柴油) engines with vegetable oil started with the inventor Rudolf Diesel. When Diesel
showed his engine at the 1900 World Exhibition in Paris, it was running only on peanut oil, a kind of biodiesel.
According to the United Soybean Board, biodiesel is a fuel made from vegetable oils or animal fats.
However, over the next 100 years, diesel fuel was made largely from petroleum (石油). Interest was
renewed in biodiesel in the mid-1970s when the energy shortage occurred, and gas prices surged upward
throughout the United States. In spite of these conditions, commercial production did not take place until much
later. In 1999, The National Biodiesel Board reported that 500 000 gallons per day were produced. In 2000,
production increased t0 6. 7 million gallons per day.
With the continual rising costs of petroleum products in the new century, major corp orations and the
United States government have looked to new markets. Farmers are encouraged to grow soybeans in their
fields, as the demand for soybean fuel increases. They can now get several gallons of fuel per acre of soybean.
Biodiesel is created by removing a thick liquid called glycerin from soybean oil. It is registered with the
US Environmental Protection Agency as a pure fuel, which is known as B100, or as a fuel additive, which is
called B20, a mixture of 20 percent soy and 80 percent petroleum-based diesel.
There are many benefits of soybean fuel.
Studies have shown that biodiesel from vegetable oil reduces petroleum consumption when used in place
of petroleum diesel.
In addition, the use of biodiesel reduces CO2 in the earth"s atmosphere. This is due to the fact that growing
soybeans consumes nearly four times as much CO2 as the amount of CO2 produced from biodiesel waste
gases.
If you ever want to take a ride in a car or bus powered by soybeans, you can. The Agriculture Research
Center (ARS) National Visitor Center bus, which is used for Beltsville, Maryland farm tours, is running on
biodiesel fuel.
ARS scientists are conducting biodiesel fuel research, and they are trying to find ways to make fuel from
vegetable oils, animal fats, and used restaurant oils.
Biodiesel fuel costs more than regular diesel fuel. However, the price may drop if people use it more. We
can look to the future with the hope that clean fuel sources will continue to be widespread in the United States
and even around the world.
| 1. Maintain a regular bed and wake time schedule Go to bed at the same time every night. Choose a time when you normally feel tired, so that you don"t toss or turn. Try not to break this routine on weekends when it may be tempting to stay up late. If you want to change your bedtime, help your body adjust by making the change in small daily increments, such as 15 minutes earlier or later each day. As with your bedtime, try to maintain your regular wake-time even on weekends. 2. Fight after-dinner drowsiness (睡意) If you find yourself getting sleepy way before your bedtime, get off the couch and do something mildly stimulating to avoid falling asleep, such as washing the dishes, calling a friend, or getting clothes ready for the next day. If you give in to the drowsiness, you may wake up later in the night and have trouble getting back to sleep. 3. Keep your room dark and cool When it"s time to sleep, make sure that your environment is dark. Even dim lights- especially those from TV or computer screens-can confuse the body clock. Heavy curtains or shades can help block light from windows, or you can try an eye mask to cover your eyes. The temperature of your bedroom also affects sleep. A bedroom that is too hot or too cold can interfere with quality sleep. 4. Turn off your television Many people use the television to fall asleep or relax at the end of the day. You may even have a television in your bedroom. However, television actually stimulates the mind, rather than relaxing it. Part of this is due to content. Late night news and prime time shows frequently have disturbing, violent material. Even non-violent programming can have commercials that are jarring and loud. 5. Exercise early Exercise helps promote restful sleep if it is done several hours before you go to bed. Exercise can help you fall asleep faster and sleep more soundly-as long as it"s done at the right time. Try to finish exercising at least three hours before bed or work out earlier in the day. 6. Consult your doctor Use a sleep diary and talk to your doctor. Note what type of sleep problem is affecting your sleep or if you are sleepy when you wish to be awake and alert. Try these tips and record your sleep and sleep-related activities in a sleep diary. If problems continue, discuss the sleep diary with your doctor. There may be an underlying cause and you will want to be properly diagnosed. Your doctor will help treat the problem or may refer you to a sleep specialist. |