4. 他开车太粗心了，导致了严重的事故。

　　He drove his car too carelessly, ________________.

　　5. 当你过这座狭窄的桥时一定要保持平衡。

　　When you cross the narrow bridge, you must ________________.

　　Ⅳ.阅读理解

　　A

　　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 had seen more and more forests disappearing and 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 earth healthy while using its supply of natural resources.

　　Today, sustainable development is a proper trend in many countries. According to a recent study, the global market for low­carbon 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 revolution. It is now trying hard to make full use of wind and solar energy, and is spending a huge amount of money making electric cars and high­speed 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 by more than 50%.

　　Governments can fully develop the potential of these new markets. First, they can set high targets for reducing carbon emission (排放) and targets for saving and reusing energy. Besides, stronger management 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 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 abundant new chances for sustainable product industries.

　　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 forests