Today there are 6 billion people on the earth．By the year 2050, there may be 12.5 billion．There are a lot of people to feed．We need more food．
One way to produce more food is by growing stronger plants．For thousands of years, farmers have made plants better．Every season, they pick the best plants for the next season．It works very slowly．Since 1983, scientists have been able to change plants more quickly by changing their genetic material(遗传物质)．Foods from plants grown in this way are called genetically modified foods(转基因食品), or GM foods．
By changing the genetic material of a plant, it is possible to make new plants．They make plants which are strong against plant diseases．They can also help with our diseases：a kind of rice is being prepared, for example, which stops people from becoming blind．
Rich countries produce GM foods because they are easy to grow and bring in more money．Poor countries are interested in them because they help produce more food．
GM plants are not natural．No one knows how good or bad they are．Making GM foods is the only way of feeding people in 2050．There're strong feelings against them, because they are unnatural．They may feed people, and then hurt them or their children later．But, both rich and poor countries are very interested in their use, and they are not going to go away．In 2050, we may think differently about them．
Jeanne Calment took up skating at age 85, made her first movie appearance at age114．and held a concert in the neighborhood on her 121 st birthday．
When it comes to long life, Jeanne Calment is the world’s recordholder．She lived to the ripe old age of 122．So is 122 the upper limit(限制)to the human life span(寿命)?If scientists come up with some sort of pill or diet that would slow aging, could we possibly make it to 150－or beyond?
Researchers don't entirely agree on the answers．“Calment lived．to 122, SO it wouldn't sul33rise me if someone alive today reaches 130 or 135,”says Jerry Shay at the University of Texas．
Steve Austad at the University of Texas agrees．“People can live longer than we think．”he says．“Experts used to say that humans couldn’t live past 110．When Calment blew past that age, they raised the number to 1 20．So why can’t we go higher?”
The trouble with guessing how old people can live to be is that it’s all just guessing．“Anyone can make up a number．”says Rich Miller at the University, of guessing
Michigan．“Usually the scientist who picks the highest number gets his name in Time magazine．”
Won’t new anti－aging techniques keep us alive for centuries?Any cure, says Miller, for aging would probably keep most of HS living until about 120．Researchers are working on treatments that make the life span of mice longer by 50 percent at most．
So, if the average(平均)human life span is about 80 years, says Miller,“adding another 50 percent would get you to 120．”
So what can we learn from this little disagreement among the researchers?That life span is flexible(有弹性的), but there is a limit, says George Martin of the University of Washington．“We can get flies to live 50 percent longer．”he says．“But a fly'snever going to live 150 years．”Of course, if you became a new species(物种), one that ages at a slower speed, that would be a different story, he adds．
Does Martin really believe that humans could evolve(进化)their way to longer life?“It’s pretty cool to think about．”He says with a smile．
(1)
What does the story of Jeanne Calment prove to us?
[ ]
A．
People can live to 122．
B．
Old people are creative．
C．
Women are sporty at 85．
D．
Women live longer than men．
(2)
According to Steve Austad at the University of Texas, ________
[ ]
A．
the average human life span could be 110
B．
scientists cannot find ways to slow aging
C．
few people can expect to live to over 150
D．
experts aren’t sure how long one can live
(3)
Who thinks that a scientist will become famous if he makes longevity?
[ ]
A．
Jerry Shay．
B．
Steve Austad．
C．
Rich Miller．
D．
George Martin．
(4)
What can we infer from the last three paragraphs?
[ ]
A．
Most of us could be good at sports even at 120．
B．
The average human life span cannot be doubled．
C．
Scientists believe mice are aging at a slower speed than before．
D．
New techniques could be used to change flies into a new species．
We have three kinds of pizzas，small，medium and large．A small pizza with pepperoni．onions and olives is \$ 3.5．A medium pizza with mushrooms． tomatoes and cheese is \$ 4．0．A large pizza with olives and cheese is \$4．7．
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The Californian pizza with mushrooms，olives and green peppers is just \$3．00．The pizza with pepperoni and olives is \$ 2.50．The hot dog is \$ 1．50． The lemonade is \$ 1．00．The juice is \$ 0．5．
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(1)
If you want to buy a small pizza，a medium pizza and a large pizza, you can pay _____ .
A．\$12．20 B．\$8．20 C．\$8．70 D．\$12．70
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(2)
If you go to the House of Pizza，you can buy 3 medium pizza with _____ on it．
A．pepperoni,onions and olives
B．olives and cheese
C．green peppers and onions
D．mushrooms，tomatoes and cheese
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(3)
If you only have \$1．50 with you，you can buy _____ at lunch time．
A．a pizza with green peppers and onions on it
B．a pizza with cheese and tomatoes on it
C．the pizza and salad lunch
D．a pizza with pepperoni and cheese
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(4)
If you want to order a pizza，you can _____ ．
A．go to the House of Pizza B．get a lunch special
C．call 825-3933 D．go to the Pizza Express
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(5)
In the House of Pizza，you can buy _____ ．
A．lemonade B．juice C．iced tea D．a large pizza
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阅读理解
Good afternoon.Welcome to England.We hope that your visit will be a pleasant one.Today I'd like to tell you something about a few of our laws.
The first one is about drinking.Now you may not buy wine in this country if you are under 18 years of age,nor may your friends buy it for you.
The second one,noise.Enjoy yourselves by yourself,but don't make unnecessary noise,especially at night.We ask you to respect other people who may wish you be quiet.
The third one,crossing the road.Be careful.The traffic moves on the left side of the road in this country.Use pedestrian crossing (人行横道) and don't take any chances when crossing the road.
My next point is about rubbish.It isn't lawful to drop rubbish in the street.When you have something to throw away,please put it in your pocket and take it home,or put it in a dustbin.
Finally,smoking.It is against the law to buy cigarettes if you are less than 16 years of age.
I'd like to finish by saying that if you need any kinds of help,you should contact the police.They will be glad to help you.You can call,write or go to ask any policemen.
(1)
Who do you think is most likely to make the speech?
A.A guide. B.A person who makes laws.
C.A teacher. D.An English officer.
[ ]
(2)
How many laws are discussed in the speech?
A.Four. B.Three. C.Six. D.Five.
[ ]
(3)
The main purpose (目的) of this speech is to ______.
A.tell people that those above 18 can drink and smoke in England
B.declare (宣布) the different laws in England
C.give advice to the travelers in England
D.warn people against going to England
[ ]
(4)
The underlined word“contact”in the last paragraph means“______”.
A.keep up B.go to see C.make a call to D.bring trouble
[ ]
(5)
From the passage we can learn______.
A.in England,if you are under 18 years of age,you can't buy wine,but your friends can buy it for you
B.you may not buy cigarettes unless you are above 16 years of age
C.because the traffic moves on the left side of the road,you must use the pedestrian crossing when crossing the road
