I think that genetically modified foods should be banned．Here's why．

We have no idea of the real impact they have on our environment．While there's currently no hard proof that environmental damage is being done by genetically modified foods, there are a few worrying and suspect events that may actually be tied to these products．Most important is the sudden loss of huge numbers of bee hives．Bees are necessary to the pollination process for soybeans and many other food crops．It's entirely possible that "the law of unintended consequences" has caused the loss of these extremely important insects．

There's also no real way to prevent cross contamination （交叉污染） between modified crops and natural crops．When neighboring fields are planted with different varieties of computable（可共存的） plants, there is a  virtual guarantee of some cross pollination between the fields．

We have no idea of the real impact they have on human beings．There is already documented evidence that genetically modified foods may be the cause of higher allergy （过敏） rates in children, It's impossible to guess v/hat other effects they may eventually cause．

I suspect that most people have forgotten the serious health scare and complete failure that occurred in 1989 that caused death or health problems for hundreds of people．The product causing the problem was L-tryptophan, an amino acid; Commercially produced L-tryptophan is developed through a bacterial fermentation process．One maker of the supplement developed a genetically modified strain of bacteria which was capable of producing higher quantities of L-tryptophan．

Unfortunately, the process "broke" somewhere along the line with the genetically altered bacteria creating an altered form of the chemical which had devastating effects on people who consumed it．

Since there is no way to predict these kinds or changes, it's both foolish and dangerous to introduce genetically modified products into the food chain.

Finally, there's no need for genetically modified foods．Most companies that produce these products will send out statistics about higher output per acre or plants that are more tolerant to negative conditions．But the truth is that the claims, while at least partially true, are mostly rhetoric．

These companies are really just looking for a way to increase their bottom line profits．They may not actually intend to, damage the ecosystem or create new health problems for people．But in my opinion it's not nice to fool Mother Nature．She may offer up a variety of severe surprises in response．

68．What's the structure of the passage?

69．The sudden loss of bee hives may be due to ___       .

       A．environmental pollution from human beings

       B．genetically modified products

       C．cross-contamination between modified crops

       D．cross pollination between the fields

70．Which of the following words best describes genetically modified foods?

       A．Risky．           B．Deadly.         C．Harmful．                 D．Healthy．

71．Most companies advocate the genetically modified products in order to _     _．

       A．increase their output                    B．solve health problems

       C．earn more money                         D．protect the ecosystem  

阅读理解

The Pentagon

五角大楼

    美国号称世界头号军事大国，其武力干涉几乎渗透到全球，有人开玩笑说：“只要五角大楼打个喷嚏，整个地球都会震动。”五角大楼是什么? 让我们揭开它神秘的面纱，好好地认识一下这座建筑的运作职能吧。

    The Pentagon，or the headquarters of the US Department of Defense，is one of the largest office buildings in the world，taking up a total land of 583 acres．The five-sided structure itself occupies an area of 29 acres．Each of its five outside wails is 921 feet long．It has three times the floor space as the Empire State Building or half again as much space as either of the New York's World Trade Center towers．

    Working inside this huge building are over 25 000 employees，one half of them being civilians and the other half members of the U．S． armed forces．During the last year of the Second World War there were 37 000 people，both military and civilian，working inside the Pentagon．In the Korean and Vietnam War periods，31 000．The employees are scattered among hundreds of offices that occupy a floor space of 3705793 square feet．

While inside the building they tell time by 4 200 clocks，drink from 685 water fountains，utilize 280 rest rooms，consume 30 000 cups of coffee，6 000 tins of milk and 5 000 bottles of soft drinks of various kinds every day，with a total staff of 600 persons preparing and serving food and drinks to the Pentagon employees，daily．

    Notes

    Pentagon n．五边形；五角大楼　　  civilian n．平民

    military n．军人　　　　　　　　  scatter v．分散

    utilize v．利用；应用　　　　　　 consume v．消耗

    Comprehension question

The building is called “the Pentagon ”because________．

A．it is the largest building in the world

B．it lies in the U．S．A．

C．it has five sides

  D．it is a secret place

Sports shoes that work out whether their owner has done enough exercise to warrant time in front of the television have been devised in the UK.

The shoes — named Square Eyes — contain an electronic pressure sensor and a tiny computer chip to record how many steps the wearer has taken in a day. A wireless transmitter(传话器) passes the information to a receiver connected to a television, and this decides how much evening viewing time the wearer deserves, based on the day’s efforts.

The design was inspired by a desire to fight against the rapidly ballooning waistlines among British teenagers, says Gillian Swan, who developed Square Eyes as a final year design project at Brunel University to London, UK. “We looked at current issues and childhood overweight really stood out,” she says. “And I wanted to tackle that with my design.”

Once a child has used up their daily allowance gained through exercise, the television automatically switches off. And further time in front of the TV can only be earned through more steps.

Swan calculated how exercise should translate to television time using the recommended daily amounts of both. Health experts suggest that a child take 12,000 steps each day and watch no more than two hours of television. So, every 100 steps recorded by the Square Eyes shoes equals precisely one minute of TV time.

Existing pedometers （计步器） normally clip onto a belt or slip into a pocket and keep count of steps by measuring sudden movement. Swan says these can be easily tricked into recording steps through shaking. But her shoe has been built to be harder for lazy teenagers to cheat. “It is possible, but it would be a lot of effort,” she says. “That was one of my main design considerations.”

51.According to Swan, the purpose of her design project is to ________.

A.keep a record of the steps of the wearer                     

B.deal with overweight among teenagers

C.enable children to resist the temptation of TV

D.prevent children from being tricked by TV programs

52.Which of the following is true of Square Eyes shoes?

A.They regulate a child’s evening TV viewing time.       

B.They determine a child’s daily pocket money.

C.They have raised the hot issue of overweight.

D.They contain information of the receiver.

53.What is stressed（强调）by health experts in their suggestion?

A.The exact number of steps to be taken.

B.The precise number of hours spent on TV.

C.The proper amount of daily exercise and TV time.

D.The way of changing steps into TV watching time.

54.Compared with other similar products, the new design ________.

A.makes it difficult for lazy teenagers to cheat

B.counts the wearer’s steps through shaking

C.records the sudden movement of the wearer

D.sends teenagers’ health data to the receiver

55.Which of the following would be the best title for the text?

A.Smart Shoes Decide on Television Time               B.Smart Shoes Guarantee More Exercise

C.Smart Shoes Measure Time of Exercise               D.Smart Shoes Stop Childhood Overweight