A bite of a cookie containing peanuts coul

题型:单项选择题

问题:

A bite of a cookie containing peanuts could cause the airway to constrict fatally. Sharing a toy with another child who had earlier eaten a peanut butter and jelly sandwich could raise a case of hives. A peanut butter cup dropped in a Halloween bag could contaminate the rest of the treats, posing an unknown risk.

These are the scenarios that "make your bone marrow turn cold" according to L. Val Giddings, vice president for food and agriculture of the Biotechnology Industry Organization. Besides representing the policy interests of food biotech companies in Washington, D. C., Giddings is the father of a four-year-old boy with a severe peanut allergy. Peanuts are only one of the most allergenic foods; estimates of the number of people who experience a reaction to the beans hover around 2 percent of the population.

Giddings says that peanuts are only one of several foods that biotechnologists are altering genetically in an attempt to eliminate the proteins that do great harm to some people’s immune systems. Although soy allergies do not usually cause life-threatening reactions, the scientists are also targeting soybeans, which can be found in two thirds of all manufactured food, making the supermarket a minefield for people allergic to soy. Biotechnologists are focusing on wheat, too, and might soon expand their research to the rest of the "big eight" allergy-inducing foods: tree nuts, milk, eggs, shellfish and fish.

Last September, for example, Anthony J. Kinney, a crop genetics researcher at DuPont Experimental Station in Wilmington, Del., and his colleagues reported using a technique called RNA interference (RNAi) to silence the genes that encode p34, a protein responsible for causing 65 percent of all soybean allergies. RNAi exploits the mechanism that cells use to protect themselves against foreign genetic material; it causes a cell to destroy RNA transcribed from a given gene, effectively turning off the gene.

Whether the public will accept food genetically modified to be low-allergen is still unknown. Courtney Chabot Dreyer, a spokesperson for Pioneer Hi-Bred International, a subsidiary of DuPont, says that the company will conduct studies to determine whether a promising market exists for low allergen soy before developing the seeds for sale to farmers. She estimates that Pioneer Hi-Bred is seven years away from commercializing the altered soybeans.

Doug Gurian-Sherman, scientific director of the biotechnology project at the Center for Science in the Public Interest—a group that has advocated enhanced Food and Drug Administration oversight for genetically modified foods—comments that his organization would not oppose low-allergen foods if they prove to be safe. But he wonders about "identity preservation" a term used in the food industry to describe the deliberate separation of genetically engineered and no nengineered products. A batch of nonengineered peanuts or soybeans might contaminate machinery reserved for low-allergen versions, he suggests, reducing the benefit of the gene-altered food. Such issues of identity preservation could make low-allergen genetically modified foods too costly to produce, Chabot Dreyer admits. But, she says, "it’s still too early to see if that’s true. \

According to the text, which of the following statements is true()

A.Genetically modified foods have been supervised by the authority

B.Genetically modified foods have proved to be safe

C. The nonengineered foods absolutely can be contaminated by the engineered foods

D.The engineered foods are immediately profitable for the food companies

考点:普通考研中医综合中医综合
题型:单项选择题

期货公司申请金融期货结算业务资格,应当向中国证监会提交申请日前()个月月末的期货公司风险监管报表。

A.3

B.5

C.1

D.2

题型:单项选择题

水刹车的水量少时,会出现()的故障。

A、转子轴向移动

B、内部有异响

C、外壳发生摆动

D、制动力矩小

题型:单项选择题

阅读理解。

     High-tech machines have made life easier for millions around the world. However, some people still

prefer low-tech ways of doing things. Here's an example of why this is happening. You can microwave

a frozen hamburger in 60 seconds. However, it won't taste as good as one you cook on the stove. And

if you're in that much of a hurry, you probably won't take time to toast the bun. High-tech cooking saves

time, but it doesn't make for better-tasting meals.

     Most people get their news from high-tech sources like television or the Internet. This has many

advantages. For example, electronic news is more up to date than newspapers or magazines. It's also

more exciting to see live and videotaped news events than photographs. However, newspapers and

magazines have some important advantages. They give more background and details. They also let you

read the parts that are important to you and skip the rest.

     Other high-tech timesavers have similar disadvantages. For examples, most people use the phone or

e-mail to stay in touch with friends and family members who live in other places. But when you use the

Internet or the phone, you don't always think carefully about what you are saying, and sometimes you

forget the important things you want to communicate. Similarly, when you word-process a homework

assignment instead of handwriting it, you can check your spelling electronically and put in fancy

headings. However, some students are so busy with the computer that they don't pay enough attention

to the actual words they are writing.

1. Which of the following statements is TRUE according to the passage?

A. The writer likes high-tech cooking.

B. Low-tech cooking produces better-tasting meals.

C. High-tech news programs always keep you reading what is important to you.

D. Handwritten homework is better than word-processed homework.

2. How does the writer feel about high-tech tool?

A. Better late than never.

B. Easy come, easy go.

C. Every coin has two sides.

D. Learn to walk before you run.

3. What is the main subject discussed in the text?

A. High-tech vs. low-tech.

B. Advantages vs. disadvantages.

C. Newspapers and magazines vs. television and the Internet.

D. Word-processing vs. handwriting.

题型:单项选择题

同一轮轴上的轮胎花纹和型号应相同。

题型:单项选择题

狂犬病疫苗属于()

A.灭活疫苗

B.减毒活疫苗

C.类毒素疫苗

D.基因工程疫苗

E.DNA疫苗

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