More and more of the world's supply of seafood is coming from farms. Although the majority of the world's seafood comes from harvests in the ocean, there is a significant shift toward aquaculture (水产养殖) now.Biotechnology is contributing to high-yield aquaculture through transgenics -- moving genes from one species to another. For example, researchers introduce desirable genetic traits into fish, creating harder breeds. Some fish species have a protein that allows them to survive in the water of the North Pole. By transplanting this antifreeze gene into other species, researchers have created more fish that can survive in extremely cold water.Biotechnologists are attempting to improve a wide range of genetic traits in fish used for aquaculture, developing fish that are larger and faster growing, more efficient in turning feed into muscle, more tolerant of low oxygen levels in the water, and better able to resist diseases.Researchers are also seeking plant-based sources of food to feed fish to replace fishmeal. The use of plant protein on fish farms could take some of the pressure off wild fish stocks and address the problem of phosphorus (磷) pollution because plants do not contain high levels of phosphorus.While aquaculture provides a reliable source of protein, the industry is faced with environmental challenges. Perhaps the biggest concern is water pollution. Fish waste and uneaten food build up at farm sites and can float directly downstream into water supplies.In addition, aquaculture has low efficiency of using resources. Fish farms need protein feed, and about 17 percent of ocean fish, an overharvested wild resource, becomes food for farming fish. It is estimated that five kilograms of oceanic fish reduced into fishmeal are required to raise one kilogram of farmed ocean fish or shrimps, representing a large net protein loss.1. What does the author intend to tell us in this passage?A: The pollution caused by aquaculture.B: The development and problems in aquaculture.C: The causes of the change in traditional aquaculture.D: The advantages of biotechnology used in aquaculture.2. What is the purpose of transgenics used in aquaculture?A: To create more fish species.B: To make fish more nutritious.C: To give fish traits they do not have.D: To make fish in the North Pole live longer.3. Why are researchers looking for plant-based sources of food to feed fish?A: Plants have high levels of phosphorus.B: Plants are much healthier than fishmeal.C: Plants are more environmentally friendly.D: Plants can be found and grown very easily.4. What is one of the problems that aquaculture produces?A: Fish grows too fast on fish farms.B: Too much water is used in fish farms.C: Fish growing on fish farms lacks protein.D: Waste from fish farms pollutes water supplies.5. What is revealed by the low efficiency of aquaculture?A: Protein in farmed fish has been lost substantially.B: The number of farmed fish keeps becoming smaller.C: Only 17 percent of farmed fish has become our food.D: Farmed fish needs too much fishmeal made of oceanic fish.
More and more of the world's supply of seafood is coming from farms. Although the majority of the world's seafood comes from harvests in the ocean, there is a significant shift toward aquaculture (水产养殖) now.
Biotechnology is contributing to high-yield aquaculture through transgenics -- moving genes from one species to another. For example, researchers introduce desirable genetic traits into fish, creating harder breeds. Some fish species have a protein that allows them to survive in the water of the North Pole. By transplanting this antifreeze gene into other species, researchers have created more fish that can survive in extremely cold water.
Biotechnologists are attempting to improve a wide range of genetic traits in fish used for aquaculture, developing fish that are larger and faster growing, more efficient in turning feed into muscle, more tolerant of low oxygen levels in the water, and better able to resist diseases.
Researchers are also seeking plant-based sources of food to feed fish to replace fishmeal. The use of plant protein on fish farms could take some of the pressure off wild fish stocks and address the problem of phosphorus (磷) pollution because plants do not contain high levels of phosphorus.
While aquaculture provides a reliable source of protein, the industry is faced with environmental challenges. Perhaps the biggest concern is water pollution. Fish waste and uneaten food build up at farm sites and can float directly downstream into water supplies.
In addition, aquaculture has low efficiency of using resources. Fish farms need protein feed, and about 17 percent of ocean fish, an overharvested wild resource, becomes food for farming fish. It is estimated that five kilograms of oceanic fish reduced into fishmeal are required to raise one kilogram of farmed ocean fish or shrimps, representing a large net protein loss.
1. What does the author intend to tell us in this passage?
A: The pollution caused by aquaculture.
B: The development and problems in aquaculture.
C: The causes of the change in traditional aquaculture.
D: The advantages of biotechnology used in aquaculture.
2. What is the purpose of transgenics used in aquaculture?
A: To create more fish species.
B: To make fish more nutritious.
C: To give fish traits they do not have.
D: To make fish in the North Pole live longer.
3. Why are researchers looking for plant-based sources of food to feed fish?
A: Plants have high levels of phosphorus.
B: Plants are much healthier than fishmeal.
C: Plants are more environmentally friendly.
D: Plants can be found and grown very easily.
4. What is one of the problems that aquaculture produces?
A: Fish grows too fast on fish farms.
B: Too much water is used in fish farms.
C: Fish growing on fish farms lacks protein.
D: Waste from fish farms pollutes water supplies.
5. What is revealed by the low efficiency of aquaculture?
A: Protein in farmed fish has been lost substantially.
B: The number of farmed fish keeps becoming smaller.
C: Only 17 percent of farmed fish has become our food.
D: Farmed fish needs too much fishmeal made of oceanic fish.
题目解答
答案
解析
本题主要考查对文章内容的理解，包括水产养殖的发展、面临的问题以及相关技术的目的等。解题时需要仔细阅读文章，分析每个段落的主旨，并根据题目要求在文中找到对应的信息进行判断。
- 第一题：
- 文章开篇指出世界海鲜供应越来越依赖水产养殖，接着介绍了生物技术在水产养殖中的应用，如转基因技术，这属于水产养殖的发展方面。
- 随后又提到水产养殖面临水污染和资源利用效率低等环境挑战，这是水产养殖存在的问题。
- 综合来看，文章主要讲述了水产养殖的发展和问题，所以选B。
- 第二题：
- 根据文中“Biotechnology is contributing to high - yield aquaculture through transgenics -- moving genes from one species to another. For example, researchers introduce desirable genetic traits into fish, creating harder breeds.”可知，转基因技术是将一个物种的基因转移到另一个物种，把理想的基因性状引入鱼类，创造出更优良的品种。
- 也就是赋予鱼类原本没有的性状，而不是创造更多的鱼类物种或使鱼类更有营养，也不是让北极的鱼活得更久，所以选C。
- 第三题：
- 文中提到“The use of plant protein on fish farms could take some of the pressure off wild fish stocks and address the problem of phosphorus (磷) pollution because plants do not contain high levels of phosphorus.”
- 这表明使用植物蛋白可以减轻野生鱼类资源的压力，解决磷污染问题，说明植物更环保，而不是因为植物含磷量高、比鱼粉更健康或容易找到和种植，所以选C。
- 第四题：
- 文中明确指出“Perhaps the biggest concern is water pollution. Fish waste and uneaten food build up at farm sites and can float directly downstream into water supplies.”
- 即水产养殖的一个主要问题是养殖场的鱼粪和未吃的食物会直接流入水源，造成水污染，而不是鱼在养殖场长得太快、用水过多或缺乏蛋白质，所以选D。
- 第五题：
- 文中提到“It is estimated that five kilograms of oceanic fish reduced into fishmeal are required to raise one kilogram of farmed ocean fish or shrimps, representing a large net protein loss.”
- 说明养殖一千克的海洋鱼或虾需要五千克的海洋鱼制成的鱼粉，这体现了养殖鱼需要大量由海洋鱼制成的鱼粉，导致资源浪费，而不是养殖鱼的蛋白质大量流失、数量减少或只有17%的养殖鱼成为我们的食物，所以选D。