We produce 500 billion of plastic bags in a year worldwide and they are thrown away polluting oceans, killing wildlife and getting dumped in landfills where they take up to 1000 years to decompose. Researchers have been unsuccessfully looking for a solution.
The 16-year old Canadian high school student, Daniel Burd, from Waterloo Collegiate Institute,
has discovered a way to make plastic bags degrade(分解) in as few as 3 months, a finding that won him first prize at the Canada－Wide Science Fair, a $10 000 prize, a $20 000 scholarship, and a chance to revolutionize a major environmental issue.
Burd's strategy was simple: Since plastic does eventually degrade, it must be eaten by microorganisms (微生物). If those microorganisms could be identified, we could put them to work eating the plastic much faster than under normal conditions.
With this goal in mind, he ground plastic bags into a powder and concocted(调制) a solution of household chemicals, yeast(酵母) and tap water to encourage microbes growth. Then he added the plastic powder and let the microbes work their magic for 3 months. Finally, he tested the resulting bacterial culture on plastic bags, exposing one plastic sample to dead bacteria as a control. Sure enough, the plastic exposed to the live bacteria was 17% lighter than the control after six weeks.
The inputs are cheap: maintaining the required temperature takes little energy because microbes produce heat as they work, and the only outputs are water and tiny levels of carbon dioxide.
“Almost every week I have to do chores and when I open the closet door, I have piles of plastic bags falling on top of me. One day, I got tired of it and I wanted to know what other people are doing with these plastic bags. The answer: not much. So I decided to do something myself.” said Daniel Burd.Daniel Burd won first prize at the Canada－Wide Science Fair because________.
| A．he found a new kind of microorganism |
| B．he contributed much to environmental protection |
| C．he found a way to degrade plastics in shorter time |
| D．he could encourage microbes growth in an easier way |
Daniel Burd exposed one plastic sample to dead bacteria to ________.
| A．make the live bacteria work better |
| B．test how effective his method was |
| C．know which bacteria worked faster |
| D．control the temperature in the process |
Maintaining the required temperature takes little energy because ________.
| A．plastics can get hot easily |
| B．microbes can produce heat themselves |
| C．much carbon dioxide is produced |
| D．the temperature can be controlled |
Daniel Burd got his idea from ________.
| A．his school textbook | B．the failure of researchers |
| C．his everyday work | D．the practice of other people |
Wind is the great maker of waves. There are exceptions, such as the tidal waves, sometimes produces by earthquakes under the sea. But the waves most of us know are produced by winds blowing over the sea.Now before constructing an imaginary life history of a typical wave, we need to know certain physical things about it. A wave has height, from trough (low point)to crest (high point),and it has length—the distance from this crest to that of the following wave. The period of the wave means the time it takes for succeeding crests to pass a fixed point. None of these things stays the same— for all depend upon the depth of the water and many other matters.
The water that makes up a wave does not advance with it across the sea. Each drop of water turns around in a little circle with the passing of the wave, but returns very nearly to its original position. And it is fortunate that this is so, for if the huge masses of water that make up a wave actually moved across the sea, sailing would be impossible.
If we want to find the speed of a wave, we may use the following way:
Speeding="Wavelength×Frequency"
Here, wavelength is the distance between two high points (crests), frequency means the number of cycles per second.
41.What causes waves according to the passage?
A. Earthquakes and nothing else. B. Wind and volcanos.
C. Wind and earthquakes. D. Wind and water.
42.Which of the following is true according to the text?
A. The water of a wave moves away across the sea.
B. The water of a wave remains almost in the same place.
C. The water of a wave goes with the passing of the wave.
D. The length of a wave means the distance between crest and trough.
43.The underlined word “succeeding” means__________.
A. reaching an aim B. doing well C. following after D. taking place
44.If the speed of wave 1 is 100 cm/s, and its frequency 10;and the frequency of wave 2 is 300,while its speed is twice that of wave 1.Which of the following is true?
A. The wave-lengths of the two are equal.
B. The wave-length of wave 1 is 10 times longer than that of Wave 2.
C. The wave-length of wave 2 is longer than that of wave 1.
D. The wave-length of wave 1 is longer than that of wave 2.
Five thousand years ago, people thought that illnesses were the result of evil living in human bodies. They also believed that gods and superior spirits were punishing people through diseases. The practice of magic and witchcraft (巫术) was popular among many tribes, and charms (符咒) and images of gods to drive away the evil spirits were often used.
People also started using herbal(草药的) medicine and by trial and error (反复试验，不断摸索) learned how to cure stomachaches and fevers. They had a witch doctor in the community. He would treat people with simple herbal medicine and magic. Early medicine was practiced the way north tribal Indians did hundreds of years ago and the way some tribes practice it today.
The ancient Chinese believed that the body was ruled by two forces, which they called “yin” and “yang”. The body would become ill if one force overcame the other and the balance between them was changed. Acupuncture (针刺疗法) was the way to bring back the balance between the two.
Also sand painting was an important part of Navaho medicine. The medicine man paints loosely upon the floor of an earth-covered house, where the ceremony takes place, or on a buckskin (鹿皮) or a piece of cloth, by letting the colored sands flow through his fingers with control and skill.
Ancient Mesopotamians believed that diseases come either from an evil spirit or a physical problem, such as worms. The doctor would decide from which source the illness has come from and send the patient either to a herbalist or to a witch doctor.
Egyptians had a very advanced medicine. They would sometimes rely on the god’s power to receive healing, but they also treated illnesses and operated on minor health problems like snake bites. They sucked the blood from the wound and bound the affected limb to stop the poison from spreading.
66. The practice of magic and witchcraft was popular in ancient times because ________ .
A. people could avoid being punished by gods and superior spirits by doing this.
B. people thought they could avoid getting diseases in this way.
C. people believed the evil spirits could be driven away in this way.
D. people often got diseases and this way was very effective.
67. How many places are mentioned where early medicine existed in the passage?
A. Three. B. Four. C. Five. D. Six.
68. From Paragraph 2 we can learn that ________.
A. people can cure lots of diseases by combining herbal medicine and magic.
B. herbal medicine is so effective that it can cure all kinds of diseases.
C. witch doctors treated people only with herbal medicine.
D. people tried lots of times to cure illnesses with herbal medicine.
69. Ancient Chinese people believed that ________.
A. diseases were the result of evil living in human bodies.
B. people would fall ill if the balance in human bodies was disturbed.
C. a medicine man could cure people’s diseases by sand painting.
D. diseases not only came from evil spirits but also were physical problems
70. The passage mainly tells us ________.
A. why ancient people became ill.
B. about the most advanced medicine in ancient times.
C. about the development of herbal medicine.
D. how ancient people cured their diseases.
About ten men in every hundred suffer from color blindness in some way. Women are luckier; only about one in two hundred is affected in this matter. Perhaps, after all, it is safer to be driven by a woman!
There are different forms of color blindness. In some cases a man may not be able to see deep red. He may think that red, orange and yellow are all shadows of green. Sometimes a person cannot tell the difference between blue and green. In rare cases an unlucky man may see everything in shades of green －a strange world indeed.
Color blindness in human beings is a strange thing to explain. In a single eye there are millions of very small things called “cones”. These help us to see in a bright light and to tell difference between colors. There are also millions of “rods”, but these are used for seeing when it is near dark. They show us shape but no color.
Some insects have favorite colors. Mosquitoes prefer blue to yellow. A red light will not attract insects, but a blue lamp will. In a similar way human beings also have favorite colors. Yet we are lucky. With the aid of the cones in our eyes we can see many beautiful colors by day, and with the aid of the rods we can see shapes at night. One day we may even learn more about the invisible colors around us.
1. The passage is mainly about _____________.
A. color and its surprising effects. B. women being luckier than men
C. danger caused by color blindness D. color blindness
2. According to the passage, with the help of the “cones”, we can_______________.
A. tell different shapes B. see in a weak light
C. kill mosquitoes D. tell orange from yellow
3. Why do some people say it is safer to be driven by women?
A. Women are more careful. B. There are fewer color-blind women
C. Women are fonder of driving than men. D. Women are weaker but quicker in thinking.
4. Which of the statements about the color- blind is true?
A. Not all of them have the same problem in recognizing color.
B. None of them can see deep red.
C. None of them can tell the difference between blue and green.
D. All of them see everything in shades of green.
5. We can attract and kill mosquitoes by using a _____________.
A. red light B. yellow light C. blue light D. green light
PART THREE READING COMPREHENSION ( 30 points)
Directions: Read the following three passages. Each passage is followed by several questions or unfinished statements. For each of them there are four choices marked A, B, C and D. Choose the one that fits best according to the information given in the passage.
Young people can have problems with their minds. Some students become worried because they have to study very hard. Others have trouble getting on well with people like their parents and classmates.
Liu Wei, a Junior 2 student from Hefei, could not understand his teacher and was doing badly in his lessons. He became so worried about it that he started to cut his finger with a knife. Another student, 14-year-old Yan Fang from Guangzhou, was afraid of exams. She got very worried in the test, and when she looked at the exam papers, she couldn’t think of anything to write.
A recent report from Jiefang Daily says about 18% of Shanghai teenagers have mental (心理的) problems. Their troubles include being worried and very unhappy, and having problems in learning and getting on well with people. Many students who have problems won’t go for advice or help. Some think they will look stupid (愚蠢的) if they go to see a doctor. Others don’t want to talk about their secret.
Liang Yuezhu,an expert on teenagers from Beijing Anding Hospital has the following advice for teenagers.
1). Talk to your parents or teachers often.
2). Take part in group activities and play sports.
3). Go to see a doctor if you feel unhappy or unwell.
56.The students who often become worried or have trouble getting on well with others may have________.
A. mental problems B. a headache C. knives with them D. no parents
57. Liu Wei cut his finger with a knife because__________.
A. he was afraid of his teacher B. he wanted to frighten his parents
C. he was so worried about his study D. his finger was badly hurt
58. Yan Fang’s problems happened whenever _________.
A. she studied very hard B. she had exams
C. she talked with her parents D. she thought of something
59. Students who have problems won’t ask others for help because _________.
A. they won’t let others think they are stupid.
B. they don’t think doctors can help them.
C. they don’t want to tell their secret to others.
D. both A and C.
60. Liang Yuezhu’s advice tells us that__________.
A. it’s better for the students who have mental problems to join others.
B. it’s unnecessary for them to be with others.
C. only group activities and sports can help them.
D. teachers and parents can’t do anything about mental problems.
The year is 2094．It has been announced that a comet (彗星) is heading towards the Earth．Most of it will miss our planet , but two pieces will probably hit the southern half of the Earth．
On 17 July , a piece four kilometers wide enters the Earth’s atmosphere (大气层) with a massive explosion．About half of the piece is destroyed , but the remaining part hits the South Atlantic at 200 times the speed of sound．The sea boils and a huge hole is made in the sea bed．Huge waves are created and spread outwards from the hole．The wall of water , a kilometer high , rushes towards southern Africa at 800 kilometers an hour．Cities on the African coast are totally destroyed and millions of people re drowned．
Before the waves reach South America , the second piece of the comet lands in Argentina．Earthquakes and volcanoes are set off in the Andes Mountains．The shock waves move north into California and all around the Pacific Ocean．The cities of Los Angeles , San Francisco and Tokyo are completely destroyed by earthquakes．Millions of people in the southern half of the earth are already dead, but the north won’t escape for long．Because of the explosions , the sun is hidden by clouds of dust , temperatures around the world fall to almost zero．Crops are ruined．The sun won’t be seen again for many years．Wars break out as countries fight for food．A year later , no more than 10 million people remain alive．
Could it really happen ? In fact , it has already happened more than once in the history of the Earth．The dinosaurs were on the Earth for over 160 million years．Then 65 million years ago they suddenly disappeared．Many scientists believe that the Earth was hit by a piece of object in space．The dinosaurs couldn’t live through the cold climate that followed and they died out．Will we meet the same and ?
72．What is mainly described in the passage ?
A．A historic discovery． B．An event of imagination
C．A research on space． D．A scientific adventure．
73．When the first piece hits the South Atlantic , it causes ．
A．an earthquake B．damages to cities
C．an Earth explosion D．huge waves
74．Why can’t the northern half of the earth escape for long ?
A．Because the land is covered with water
B．Because the light and heat from the sun can not reach the earth．
C．Because people there can not live at the temperature of zero．
D．Because wars break out among countries．
75．By giving the example of dinosaurs , the author tries to prove ．
A．animals could not live in the cold climate
B．what happened 65 million years ago was an invented story
C．the human beings will die out in 2094
D．the Earth could be hit by other objects in space
粤公网安备 44130202000953号