化简:3Cn1+32Cn2+33Cn3+…+3nCnn=______.

题型:填空题

问题:

化简:3Cn1+32Cn2+33Cn3+…+3nCnn=______.

考点:二项式定理与性质
题型:填空题

支配肝脏的交感神经,其节前纤维来源于胸7~8。()

题型:填空题

For the past year, the World Food Program has operated a project to prevent hunger in twenty-one countries in Africa. In the project, the United Nations agency works with small farmers to grow more and better produce.

The World Food Program buys the produce through local cooperative associations. Then it distributes the products within the country or area. The project works mainly with women. Sheila Sisulu from the World Food Program says the project aims to break a cycle that keeps people hungry. The situation is that farmers have to sell their produce at low prices after harvest, when supplies are greatest. Then they have to pay high prices to buy food for themselves during the "lean season," when supplies are limited.

But when farmers produce more food, they can sell more. And when they produce high-quality food, they can get higher prices. They can also store food for themselves, and have enough money to buy food if they need to during the lean season. Sheila Sisulu says the farmers are now starting to earn profits through the project.

The Food and Agriculture Organization and the International Fund for Agricultural Development help the farmers choose the best seeds and fertilizers. They also advise the farmers on the quality levels that the World Food Program requires to buy their produce.

Two other groups recently launched a separate effort to increase food security in Africa. The groups are the Alliance for a Green Revolution in Africa and the New Partnership for Africa's Development. They say African governments have to increase their investment in agriculture in order to fight problems related to climate change. The groups want the governments to develop programs in seeds, soil health, policy and markets.

Former United Nations chief Kofi Annan is the chairman of AGRA. The group's president, Namanga Ngongi, says many African governments are not meeting a target of spending ten percent of their national budgets on agriculture. But he says investment has risen from four percent of national budgets to probably five and a half percent today.

1. The underlined word “lean” in Paragraph 2 probably has the same meaning with ______.

A. He is a tall, lean and handsome boy, liked by many girls.

B. The changes made the company leaner and more competitive.

C. The company recovered well after going through several lean years.

D. The doctor told him that lean meat was healthier for his mother than fatty meat.

2. According to Sheila Sisulu, the project _____.

A. distributes the products within the whole world

B. has benefited few African farmers during the past year

C. enables the African farmers to sell their produce at low prices after harvest

D. can help the farmers to get away from the situation that keeps them hungry

3. The problem of hunger in Africa can possibly be relieved by ______.

A. United Nations chief

B. the World Food Program

C. African governments and farmers

D. the Food and Agriculture Organization

4. Which can be the best title?

A. Hunger, the most serious problem in Africa      

B. Two efforts seek to increase food security in Africa

C. A project to grow more and better produce in Africa

D. More investments in agriculture by African governments

题型:填空题

先进生产力和先进文化的创造主体是()。

A.工人阶级

B.科研人才

C.知识分子

D.人民群众

题型:填空题

分泌性中耳炎治疗中,鼓膜置管术适应证不包括()

A.病情迁延,长期不愈

B.反复发作

C.胶耳

D.头部放疗后,预计咽鼓管功能不能于短期内恢复

E.小儿不合作

题型:填空题

中低压玻璃钢承插管道,单口试压完成后要立即(),防止下道口插接时管道位置移动,造成接口()失效。

更多题库