题干

在漫长的历史时期内,我们的祖先通过自身的生产和生活实践,积累了对生态方面的感性认识和经验,并形成了一些生态学思想,如人与自然和谐统一的思想。根据这一思想和生态学知识,下列说法正确的是(    )

A:生态系统的物质循环和能量流动有其自身的运行规律

B:若人与自然和谐统一,生产者固定的能量便可反复利用

C:“退耕还林、还草”是体现人与自然和谐统一思想的实例

D:人类应以保持生态系统相对稳定为原则,确定自身的消耗标准

上一题 下一题 0.0难度 选择题 更新时间:2012-08-13 01:41:34

答案(点此获取答案解析)

A,C,D

同类题4

Answer the questions(根据短文内容回答下列问题)

    Andrew Carnegie was born in 1835 in Scotland. He was from a poor family. When he was twelve, his family moved to the USA. They wanted a better life. There, Andrew started to work right away. He got a job in a factory. He was a good worker, but he didn't like the job. Later, he changed his job. He worked at the Railroad Company where everybody liked him. He did many different jobs. His salary got higher every year.

    In his free time, Andrew loved to read. But in those days, the United States didn't have free public libraries. Luckily, he lived with a rich man with many books, who let young boys use his library for free, so Andrew could read as much as possible. He read throughout his life.

    Andrew learned a lot at the railroad company. He realized that the railroad was very important for big countries. He had a idea to start a business with railroads. He saved all his money and opened a business at the age of thirty years.

    First, his company made bridges for the railroads. Ten years later, it made steel for bridges, machines, and many other things. Soon he was the richest man in the world.

    Andrew liked to make money. But he believed it was very important to help other people. In 1901, he sold his company for $480 million. He started to give away his money to make new libraries and colleges all over the United States. He built 2811 libraries. Andrew also gave a lot of money to people who worked for peace. In 1903, he gave $1.5 million to build a Peace Palace in the Netherlands.

    Andrew Carnegie died in 1919.He was eighty-four years old. During his life, he gave away nearly all of his money. He gave away over $350 million for education and peace. There are colleges, libraries, hospitals, and parks named after Andrew Carnegie.He helped millions of people all over the world to study and learn.