电抗器是如何限制线路短路电流的?

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问题:

电抗器是如何限制线路短路电流的?

考点:铁道牵引变电值班员铁道牵引变电值班员(中级)铁道牵引变电值班员(中级)题库
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Sugar—free beets(甜菜)that still taste sweet, tastier tomatoes and brighter-colored fruits and vegetables that stay ripe(熟的)longer are all foods that are being grown now. How can they

carry traits, such as being tastier, brighter, and riper? They are genetically engineered.

Genetic engineering(基因工程)is like making a change in a recipe. For example, when you make cakes, you mix together all of the usual ingredients. If you add an extra ingredient, like salt, the cakes will taste differently.

Genes are ingredients in the recipe for life. They carry the traits of living things. Your genes dictate what color hair and eyes you’ll have, how tall you’ll be, as well as many other traits. Genes carry traits for plants, too. By adding genes to a plant, you can sometimes create new traits. For example, adding a certain gene to a potato plant can make the potato plant distasteful to bugs(虫子). This makes some farmers happy because they don’t have to use chemicals to keep bugs away from their plants.

It sounds great, but some people are opposed to the idea of food that is genetically engineered. Ronnie Cummins, from the Campaign for Food Safety, is against it. He says that one of the major concerns is allergies(过敏). Supermarkets don’t always label foods that are genetically engineered. A customer could unknowingly buy food that has an added gene from another plant that he or she is allergic to. It could be dangerous.

Gary Burton from Monsanto, a seed(种子)company that engineers food, disagrees. He says his company tests for allergies. Burton believes that genetic engineering is a valuable tool for making better food. The technology can help farmers use less insecticide(杀虫剂)and grow healthier crops. Burton thinks there are many advantages.

But Cummins says that we just don’t know what will happen in the future if we keep adding genes to foods. We could mistakenly create a monster.

People have different opinions about genetic engineering. One side supports it and thinks it will only help us. The other side is opposed to playing with nature and fears health risks. Which side do you think is right?

小题1:What could be a good thing about food that is genetically engineered?

A.It’s more expensive.

B.It could taste different.

C.It requires less insecticide.

D.It’s not labeled in the supermarket.小题2:In general, who does not support the idea of genetic food?

A.People from seed companies.

B.Farmers who use engineered seeds.

C.People from the Campaign for Food Safety.

D.Scientists who create genetically engineered food.小题3:It can be inferred that          .

A.growing genetic foods will make farmers richer

B.people will eat more genetic foods in the future

C.using fewer chemicals could make the food tastier

D.there could be unknown dangers about genetic foods小题4:What is the best title of this passage?

A.Future Farming

B.Genetic Engineering

C.Foods with a Difference

D.Genetically Engineered Fruits

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全口义齿修复是否按正常牙合关系排牙的主要依据是()

A.牙槽嵴吸收程度

B.上、下颌弓间的垂直关系

C.上、下颌弓间的水平关系

D.颌弓的大小

E.颌弓的形态

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小儿上呼吸道感染常见病原体是()

A.肺炎双球菌

B.金黄色葡萄球菌

C.人肺炎支原体

D.病毒

E.真菌

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下列有关中国文化对人口发展的影响变化的叙述,错误的是

A.从早婚早育到晚婚晚育

B.从多育多子到只生一个

C.从“学而优则仕”到“全民皆商”

D.从“四海为家”到安土重迁

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建设项目法人获得建设用地许可后,必须根据该地块城市控规要求,按照建议意图具体编制项目修建性详细规划,报( )审批认可。

A.国家建设部
B.国家土地管理部门
C.规划行政主管部门
D.当地政府

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