ToomuchTVwatchingcanharmchildr-优题课

We learned that fossil fuels were formed before and during the time of the dinosaurs（恐龙）. We are using up the fuels. We can save fossil fuels by protecting and finding ways to use energy from “endless sources”, like the sun and the wind. Some people suggest that we should start using hydrogen（氢）.
Hydrogen is a colorless, smell-less gas that takes up 75 percent of the whole universe. Hydrogen is found on earth only in mixture with other elements such as oxygen, carbon and nitrogen. To use hydrogen, we must separate it from these other elements.
Hydrogen can be used in NASA’s space program as fuel for the spaceships, and in fuel cells that provide heat, electricity and drinking water for astronauts. Fuel cells are devices that directly change hydrogen into electricity. In the future, hydrogen could be used to fuel vehicles and aircraft and provide power for our homes and offices.
Hydrogen can be made from natural gas. An electrical current can also be used to separate water into its elements of oxygen and hydrogen. Some plants in the sea and bacteria（细菌） give off hydrogen through sunlight under certain conditions.
Hydrogen as a fuel is high in energy. Yet a machine that burns pure hydrogen produces almost zero pollution. NASA has used liquid hydrogen since the 1970s to drive rockets and spacecraft into orbit. Hydrogen fuel cells power the spacecraft’s electrical systems, producing clean by-product-pure water, which the crew drinks.
56. We can get hydrogen from the following EXCEPT ______ according to the passage.
A. natural gas B. water C. creature in the sea D. bacteria
57. Why could the hydrogen be used widely in the future?
A. Because it is of high quality.
B. Because it has no pollution.
C. Because it is easy to get it from all kinds of ways.
D. Because there are much hydrogen existing in the universe.
58. The passage mainly tells us ________.
A. the usage of a new energy source B. the future energy sources
C. a new energy source －hydrogenD. how to get the energy source

The bee，like the ant，is a social insect（昆虫）.Bees live in large groups in box-like houses called hives or beehives.Every bee does a certain job that helps the other members of the group.In a beehive there live three kinds of bees:the queen bee，the male bees and the worker bees.The worker bees are born to be hard-working，flying from flower to flower collecting nectar（花蜜），which is made up mostly of sugar mixed with water.Bees draw this nectar into their honey bags where some sort of liquid in their bodies turns the nectar into honey.The newly made honey flows slowly from the bees’ underside and then is stored in small cells in the hive.When the weather turns cold，and there are no flowers for them to collect nectar，the stored honey will see them through the winter months.People who raise bees and depend on bees for a living are thought of as beekeepers.A bee-keeper usually keeps hundreds of hives，and removes honey from hives and keeps it in glass bottles or jars.Honey usually appears as a clear golden-colored liquid，but this lies in the sort of flowers from which bees have taken the nectar.
66.The best title of this passage is_______.
A.The Social Habits of Bees B.Three Kinds of Bees
C.The Production of Honey D.Bee Keepers’ Work
67.Bees are regarded as social insects because they_______.
A.form themselves into a good organization
B.have learned something from human society
C.need beekeepers to arrange their jobs
D.are born to work hard
68.The color of honey in its final stage depends on the_______.
A.type of flowers which the nectar is taken from
B.amount of sugar the beekeeper gives the bees
C.season in which the nectar is collected
D.quantity of water the bees are able to drink
69.Worker bees are always busy collecting nectar in order to_______.
A.help beekeepers to earn money from honey
B.turn it into honey
C.have something to eat in winter months
D.please the queen bee at the hive
70.During the course in which nectar change into honey_______.
A.water and sunlight are necessary conditions
B.some special liquid inside bees must be in the presence
C.many complex（复杂的）chemical changes will take place
D.worker bees have to bring up what they collected into their hive

Two scientists in California now think they can find out a person’s real age.Jeffery Bada and Patricia Masters do chemical tests on teeth.When we are born the amino acids（氨基酸）in our teeth are in one form.Then，as we grow older these amino acids change into a second form.Every year，one thousandth of the amino acids changed.So，by testing just one tooth and counting the number of amino acids in each form，Bada and Masters can work out a person’s age.They tested a tooth from the body of an Eskimo（爱斯基摩人）woman who died 1 600 years ago.From the appearance of her body，she was between 50 and 60 years old when she died.The tooth test put her age at 53.Then the Russian Government sent them a tooth from an old man in Georgia.The tooth said she was 99.Her real age was 96.The Russians are now hoping to send more teeth，from the very old people without birth certificates（出生证明书）.But there are problems.Some of the centenarians（百岁老人）have lost all their teeth.The others want to keep their teeth until they drop out naturally.So the Russian Government and the American scientists have to wait and hope.
61.Jeffery Bada and Patricia Masters believe that they can tell a person’s age according to_______.
A.an experiment on his bone
B.the shape and condition of his teeth
C.a test on the amino acids within his body
D.the changing form of amino acids in his teeth
62.According to the passage，which of the following statements is true?
A.The amino acids in an adult’s teeth may differ from those in a baby’s.
B.The number of amino acids in a 20-year-old man is different from that when he was seven.
C.Amino acids in one teeth changes without affecting their forms.
D.Scientists now can tell how long a person will live by testing his teeth.
63.Why are the two scientists asked to find out some very old Russians’ age?
A.Because the Government wants to know how long these old people can live.
B.Because they have no birth certificates.
C.Because people who have tooth problems tend to live longer.
D.Because the Government wants to know their dates of birth and death.
64.In order to find out the exact age of some people over 100，both the Russian Government and American scientists_______.
A.should wait until all of them die
B.should pull out one of their teeth
C.have to wait for their teeth to drop out naturally
D.want to have their teeth pulled out
65.The central idea of the passage is_______.
A.the relationship between people’s teeth and ages
B.the relationship between amino acids and teeth
C.the contradiction（矛盾）between scientists and patients
D.the contradiction between the Government and the scientists

America is growing older. Fifty - eight years ago, only 4 out of every 100 people in the United States were 65 or older. To day, 10 out of every 100 Americans are over 65. The aging of the population will affect（影响）American society in many ways—education, medicine, and business. Quietly, the graying of America has made us a very different society—one in which people have a quite different idea of what kind of behavior（行为） is suitable（合适）at various , ages.
　　A person s age no longer tells you anything about his/her social position, marriage or health. There’s no longer a particular year in which one goes to school or goes to work or gets married or starts a family. The social clock that kept us on time and told us when to go to school, get a job, or stop working isn’t as strong as it used to be. It doesn’t surprise us to hear of a 29 - year - old university president or a 35 - year -old grandmother, or a 70 year - old man who has become a father for the first time. Public ideas are changing.
　　Many people say, “I am much younger than my mother— or my father— was at my age. ”No one says“Act your age” any more. We’ve stopped looking with surprise at older people who act in youthful ways.
　　67．It can be learnt from the text that the aging of the population in America ________ .
　　A. has made people feel younger
　　B. has changed people’s social position
　　C. has changed people’s understanding of age
　　D. has slowed down the country’s social development
　　68．The underlined word “one” refers to ________ .
　　A. a society　　　　　　　　　　　B. America
　　C. a place　　　　　　　　　　　　D. population
　　69．“Act your age” means people should ________ .
　　A. be active when they are old
　　B. do the right thing at the right age
　　C. show respect for their parents young or old
　　D. take more physical exercise suitable to their age
　　70．If a 25 - year - old man becomes general manager of a big firm, the writer of the text would most probably consider it ________ .
　　A. normal　　　　　　　　　　　　B. wonderful
C. unbelievable　　　　　　　　　　D. unreasonable

　The following are four forms about medicine. How to use the medicine is very important. Never take any by mistake.
　　1）Take the medicine with water, followed by one tablet every eight hours, as required. For further night - time and early morning, take two tablets at bedtime. Do not take more than six tablets in 24 hours. For Children six to twelve years old, go to your doctor for advice.　Reduce dosage if nervousness, restlessness or sleeplessness takes place.
　　2）Each pill of the medicine taken three times every day for fourteen years old. As usual, a pill 6∶00 a. m., before breakfast, one before 11∶00 and one before sleep. Not for children under six years old and old persons with heart attack.
　　3）The medicine for a person with a fever. Once two pills a day before sleep for adult. Not take the medicine without fever. Half for Children under 12 years old. Children with a high fever, go to see a doctor.
　　4）The medicine taken three times a day, once five pills for adult with a cold. Half of the pills for children 10 years old. Take the medicine before breakfast, lunch, supper or before sleep.
　　60．Obviously a kind of medicine can’t be proper for ________, judging from the information.
　　A. children over twelve years old
　　B. some old persons with a fever
　　C. some old persons with heart attack
　　D. neither adults nor heart attack
　　61．When a person has a cold, he had better ________ .
　　A. have about more than fourteen pills a day
　　B. have twice a day
　　C. have four times a day
　　D. have nine pills a day
　　62．How many kinds of medicine are used for the children six years old?
　　A. All of them．
　　B. Three kinds of medicine.
　　C. Two kinds of medicine.
D. Almost not any medicine.

A．have had computers in their bedrooms	B．not be interested in math
C．be unable to go to college	D．have watched a lot of TV

A．Computers or Television	B．Studies on TV and College Education
C．Effects of Television on Children	D．Television and Children’s Learning Habits