醋酸纤维素薄膜电泳α1区带不包括（） A.IgA B.IgG C.IgM D.CRP

识图题。

下图是清初中俄边界示意图。

请回答：

（1）清军成功反击沙俄侵略军的雅克萨是图中的__________（填英文字母）。 

（2）__________年，中俄历史上第一个边界条约《尼布楚条约》签订的地点是图中的__________（填英文字母）。

（3）《尼布楚条约》的签订有什么作用？

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贴现一张面额为2000元的银行承兑汇票，4个月后到期，年贴现率为12％，贴现息为（）。

A.80

B.60

C.70

D.90

确定肺结核是否为传染源的最主要依据是（）

A.血沉检查

B.X线检查

C.痰结核菌检查

D.结核菌素试验

E.血结核抗体检查

投资者在金融市场上通过竞拍来购买公债，这是属于（）

A.承购包销方式 

B.委托出售方式 

C.公募招标方式 

D.行政分配方式

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. \

What can be inferred about genetically modified foods from the text（）

A. People do not accept any genetically modified foods

B. All genetically modified foods will be of benefit to people’s health

C. Genetically modified foods still have a long way to go

D. Genetically modified foods will soon be sold in supermarkets