问题 问答题 简答题

简述蛋白质在瘤胃中的代谢规律.

答案

参考答案:

(1)、饲料中的蛋白质到达瘤胃后,一部分蛋白质可以被瘤胃微生物降解为肽类、氨基酸和氨。这一部分蛋白质被称为瘤胃可降解蛋白。

(2)、同时瘤胃微生物可以利用这些降解产物合成本身的蛋白质。这部分蛋白质被称为微生物蛋白质。

(3)、另外一部分蛋白质在瘤胃中不能被降解。这一部分蛋白质被称为瘤胃非降解蛋白。

(4)、微生物蛋白和瘤胃非降解蛋白一起流入后部消化道,被牛消化吸收。

阅读理解

In a world with limited land, water and other natural resources(资源), the harm from the traditional business model is on the rise. Actually, the past decade has seen more and more forests disappearing and the globe becoming increasingly warm. People now realize that this unhealthy situation must be changed, and that we must be able to develop in sustainable(可持续的)ways. That means growth with low carbon or development of sustainable products. In other words, we should keep the healthy while using its supply of natural resources.

Today, sustainable development is a popular trend in many countries. According to a recent study, the global market for low-carbon energy will become three times bigger over the next decade. China, for example, has set its mind on leading that market, hoping to seize chances in the new round of the global energy resolution. It is now trying hard to made full use of wind and solar energy, and is spending a huge amount of money making electric cars and high-speed trains. In addition, we are also seeing great growth in the global markets for sustainable products such as palm oil(棕榈油), which is produced without cutting down valuable rainforest. In recent years the markets for sustainable products have grown more than 50%.

Governments can fully develop the potential of these new markets. First, they can set high  targets for reducing carbon emissions(排放) and targets for saving and reusing energy. Besides, stronger arrangement of public resources like forests can also help to speed up the development. Finally, governments can avoid the huge public expenses that are taking us in the wrong direction, and redirecting some of those expenses can accelerate the change from the traditional model to a sustainable one.

The major challenge of this century is to find ways to meet the needs of a growing population within the limits of this single planet. That is no small task, but it offers a large of new chances for sustainable product industries.

小题1:The traditional business model is harmful because of all the following EXCEPT that____.

A.it makes the world warmer

B.it consumes natural resources

C.it brings severe damage to future

D.it makes growth hard to continue小题2:What can we infer from Paragraph2?

A.China lacks wind and solar energy

B.China is the leader of the low-carbon market

C.High-speed trains are a low-carbon development

D.Palm oil is made at the cost of valuable forests小题3:To fully develop the low-carbon markets, governments can______.

A.cut public expenses

B.forbid carbon emission

C.develop public resources

D.encourage energy conservation小题4:We can learn from the last paragraph that business have many chances to _______.

A.develop sustainable products

B.explore new natural resources

C.make full use of natural resources

D.deal with the major challenge小题5:What is the main purpose of the passage?

A.To introduce a new business model

B.To compare two business models

C.To predict a change of the global markets

D.To advocate sustainable development

单项选择题