怎样计算具有一定圆角半径的弯曲件展开长度？

根据下列句子所给汉语意思或单词首字母，写出空缺处各单词的正确形式。

1. The headmaster wants to have the opening speech d______ by our English teacher next month.

2. Dr Yuan searched for a way to increase rice harvests without _____ (扩大) the area of the fields. 

3. The problem is so ______ (令人迷惑) that few people can work it out.

4. There is a general ______ (信念) that things will soon get better.

5. The boy lifted the stone with all his ______ (力量).

6. Many of the young ______ (一代) enjoy foreign music and films.

7. I know you don`t like her but try not to make it so ______ (明显).

8. A recent survey showed that 53.3 percent of China's middle-class people were not s______ (满意) with

    their physical and mental conditions. 

9. World Expos have excited and______ (鼓舞) more and more people in the world. 

10. By r______ (减少)excess emissions (过度排放) of greenhouse gases, we can put the low-carbon

      lifestyle into practice gradually.

知识分子在社会主义现代化建设中是应当团结的力量。（）

人字桅杆的两脚间应有连接绳，防止桅杆脚受力时向外滑移。

保护妇女合法权益的方式方法的法律保护包括()。

A.立法保护

B.司法和执法保护

C.法律知识的宣传教育

D.法律服务和援助

E.工会保护

Many people are concerned about the economic condition of developing countries — countries whose average per capita GNP is a fraction of that in more industrialized countries. However, for the developing countries, there exist many obstacles to their economic development.

One major obstacle to economic development is population growth. (46) The populations of most developing countries grow at a rate much faster than those of industrialized countries, and the population of some of them is so large that there is barely enough fertile land and other resources to support it. Many less developed countries depend extensively on agriculture, adding to the problem. In these countries, an incentive to have many children exists. (47) Most farms are worked by families, and children can work in the fields at an early age because most farmers believe that more children means more workers. In addition, having many children ensures the parents that someone will look after them in their old age.

Another problem for developing countries is increasing average life expectancy—the average remaining lifetime for persons who reach a certain age. Better education, international aid, and emphasis on health-care facilities help people live longer. A high life expectancy coupled with a high crude birthrate makes it difficult to increase per capita GNP.

Another obstacle to economic growth is limited natural resources. No country can develop beyond its resource potential. Unproductive land or a harsh climate can limit economic growth. (48) Some countries may be fortunate enough to discover a valuable mineral to finance their economic development, but most focus on agriculture and, as a result, their economic growth is hindered by the shortage of natural resources or energy sources needed for industry.

Still another obstacle to economic development is a lack of appropriate education and technology. Any developing countries do not have a highly literate population or the high level of technical skills needed to build an industrial society. In addition, most do not have money to train engineers and scientists. (49) Many developing countries cannot even afford to provide free public education for school-age children, and in those that can, not every child is able to take advantage of it because most of them have to work to help feed their families. As a result, much of the population may not have the basic skills needed to continue with higher education when it is offered.

Government also can be an obstacle to economic development. A country whose government often changes will have a hard time developing economically. Such constant changes impede long-term planning. (50) Economic development is made even more difficult if the political changes occur through violent revolution where industrial facilities may be destroyed.

(50) Economic development is made even more difficult if the political changes occur through violent revolution where industrial facilities may be destroyed.