题目内容
Before going outside in the morning, many of us check a window thermometer(温度计)for the temperature. This helps us decide what to wear.__1.__. We want our food to be a certain coldness in the refrigerator. We want it a certain hotness in the oven. If we don’t feel well, we use a thermometer to see if we have a fever. We keep our rooms a certain warmth in the winter and a certain coolness in the summer.
Not all the thermometers use the same system to measure temperature. We use a system called the Fahrenheit scale. But most other countries use the Centigrade scale.
Both systems use the freezing and boiling points of water as their guide.__2.__.
The most common kind of thermometer is made with mercury(水银)inside a clear glass tube. As mercury (or any other liquid ) becomes hot, it expands. As it gets colder, it contracts(收缩). That is why on hot days the mercury line is high in the glass tube.__3.__.
First. Take a clear glass juice bottle that has a cap ; fill the bottle with coloured water. Tap a hole in the center of the cap using a hammer and thick nail. Put the cap on the jar. Then stick a plastic straw(吸管) through the nail hole.____4.____.
Finally. Place a white card on the outside of the bottle and behind the straw. Now you can see the water lever easily. ____5.____.
As the temperature goes down, the water will contract, and the lever in the straw will come down. Perhaps you will want to keep a record of the water lever in the straw each morning for a week.
A.People use thermometers which are made by themselves when travelling around the world. |
B.We use and depend on thermometers to measure the temperature of many other things in our daily lives. |
C.Thermometers measure temperature, by using materials that change in the same way when they are heated or cooled. |
D.Now that you know this rule you can make a thermometer of your own that will work. |
E.The water will rise in the straw. As the temperature of the air goes up, the water will expand and rise even higher.
F.They label these in different ways. On the Fahrenheit scale water freezes at 32 degrees and boils at 212 degrees. On the Celsius scale water freezes at 0 degrees and boils at 100degrees.
G.Take wax (you may use an old candle if you have one) and melt some of it right where the straw is struck into the cap to seal(把..粘住) them together.
1.B
2.F
3.D
4.G
5.E
【解析】略
People who are outdoors in cold weather should avoid actions like suddenly lifting a heavy basket full of snow. Even walking through heavy, wet snow can strain a person’s heart.
Many people aren’t conditioned to the physical stress of outdoor activities and don’t know the dangers of being outdoors in cold weather. Those who like winter sports can suffer accidental hypothermia if they don’t make certain preparations.
Hypothermia means the body temperature has fallen below normal. It occurs when your body can’t produce enough energy to keep the internal (内部的) body temperature warm enough. It can kill you. Heart failure causes most deaths in hypothermia.
Children, the elderly and those with heart disease are at special risk. As people age, their ability to keep a normal internal body temperature often decreases. Elderly people can suffer hypothermia without knowing they’re in danger because they can’t notice the cold conditions as quickly as the young.
Besides cold temperatures, high winds, snow and rain can also steal body heat. Wind is especially dangerous because it removes the layer of heated air from around your body. At 30 degrees Fahrenheit in a 20-mile-per-hour wind, the cooling effect is equal to calm air at four degrees. Similarly dampness (湿气) causes the body to lose heat faster than it would at the same temperature in drier conditions.
To keep warm, wear more clothes. This traps air between layers. Also, wear a hat or head scarf. Much of your body’s heat can be lost through your head. Keep your hands and feet warm, too, as they tend to lose heat rapidly.
Don’t drink alcohol before going outdoors or when outside. Alcohol makes you feel warm at first because blood vessels in the skin expand. But heat is then drawn away from the body’s important organs.
【小题1】The underlined word “strain” in Paragraph 1 means ________.
A.injure | B.warm | C.control | D.burn |
A.It means the body temperature falls rapidly. | B.Most heart attacks are caused by it. |
C.It is not as scary as people think. | D.It can threaten a person’s life. |
A.they like exercising outside in cold mornings |
B.they can’t notice cold conditions if they are not told |
C.their body temperature is generally lower than young people’s |
D.their ability to keep a normal internal body temperature is not so good |
A.What causes the body to lose heat faster. | B.The advantages of drier conditions. |
C.What else can steal body heat. | D.Dangers of high winds. |
A.Feeling warm at first | B.The body’s heat is taken away |
C.Blood vessels in the skin expand | D.The risk of hypothermia is reduced |
To get an extra 14 years of life, don’t smoke, eat lots of fruits and vegetables, exercise regularly and drink alcohol in a proper amount. That is according to a study published this Monday in the Public Library of Science Medicine Journal.
After tracking more than 20,000 people aged 45-79 years in the United Kingdom from about 1993-2007, Kay-Tee, Khaw of the University of Cambridge and his colleagues found that people who adopted these four healthy habits lived an average of 14 years longer than those who didn’t.
“We’ve known for a long time that these behaviors are good things to do, but we’ve not seen this benefit before, ” said Susan Jebb, head of Nutrition and Health at Britain’s Medical Research Council. “The benefit was also seen regardless of whether or not people were fat and what social class they came from.”
Study participants(参与者)scored a point each for not smoking, regular physical activity, eating five servings of fruits and vegetables a day and moderate alcohol intake.
Public health experts said they hoped the study would inspire governments to introduce policies helping people to adopt these changes.But because the study only observed people rather than testing specific changes, it would be impossible to conclude that people who suddenly adopted these healthy behaviors would surely gain 14 years.
“We can't say that any person could gain 14 years by doing these things, ”said Dr.Tim Armstrong, a physical activity expert at the World Health Organization.“The 14 years is an average across the population of what's theoretically(理论上地)possible.”
“Most people know that things like a good diet matter and that smoking isn't good for them, ”Susan Jebb said.“We need to work on providing people with much more practical support to help them change.”
【小题1】Which of the following DOESN'T belong to the four healthy habits?
A.Eat five servings of fruits and vegetables a day. |
B.Do proper exercise in the morning every day. |
C.Drinking alcohol in the proper amount every day. |
D.Having a cigarette before going to bed every day. |
A.Susan Jebb did not take part in the study. |
B.the study observed people as well as tested specific changes. |
C.there's no need for people under 45 to adopt these good habits. |
D.only those from first class can benefit from these healthy behaviors. |
A.All the people are well aware of the harm of their bad habits. |
B.People aged 45 to 70 have bad habits in the United Kingdom. |
C.Governments should take measures to help people change their bad habits. |
D.People have adopted the four healthy habits after knowing they're good. |
A.Smoking and Drinking Cuts You 14 Years |
B.How to Live a Much Healthier Life |
C.Healthy Habits May Give Extra 14 Years |
D.How to Make Your Life Longer Than Others |