平移的基本性质是：图形经过平移，对应（ ）和对应（ ）分别相等，对应点所连舶线段

大雨过后，大量的蚯蚓钻出地面，这是因为（　　）

A．土中温度低

B．土中缺乏氧气

C．蚯蚓外出摄食

D．蚯蚓外出运动

2006年，太原市免除了19．4万名农村学生和城市贫困学生的学杂费，为4．1万名贫困生免费提供了教科书，为9000余名寄宿学生提供了生活补助；通过设立专门学校、安排专项资金等措施，保证农民工子女在城市享有受教育的机会。以上举措 [ ]

A．说明我市城乡发展的不平衡状况已得到根本改善

B．体现了教育公平的理念，对维护社会稳定发挥了重要作用

C．体现了我国义务教育的强制性

D．说明国际竞争归根结底是人才的竞争

如图所示，物体A、B都处于静止状态，其质量分别为m_A=5kg，m_B=10kg，OB呈水平，OP与竖直方向成37 º角。求物体B受到的摩擦力为多少？

British scientists are breeding a new generation of rice plants that will be able to grow. in soil con­taining salt water. Their work may enable abandoned farms to become productive farms once more.

Tim Flowers and Tony Yeo, from Sussex University’s School of Biological Sciences,. have spent several years researching how crops, such as rice, could be made to grow in water that has become salty. The pairs have recently begun a three-year programme, funded by the Biotechnology and Bio­logical Sciences Research Council, to establish which genes enable some plants to survive salty condi­tions. The aim is to breed this capability into crops, starting with rice.

It is estimated that each year more than 10 million hectares (公顷) of agricultural land are lost because salt gets into the soil and stunts(防碍生长) plants. The problem is caused by several factors. In the tropics, mangroves that create swamps (沼泽) and traditionally formed barriers to sea water have been cut down. In the Mediterranean, a series of droughts have caused the water table to drop, allowing sea water to seep (渗透) in. In Latin America, irrigation often causes problems when water is evaporated by the heat, leaving, salt deposits behind.

Excess salt then enters the plants and prevents them functioning normally. Heavy concentrations of minerals in the plants stop them drawing up the water they need to survive.

To overcome these problems. Flowers and Yeo decided to breed rice plants that take in very little salt and store what they do absorb in cells that do not affect the plants’ growth. They have started to breed these characteristics into a new rice crop, but it will take about eight harvests before the resul­ting seeds are ready to be considered for commercial use.

Once the characteristics for surviving salty soil are known, Flowers and Yeo will try to breed the appropriate genes into all manners of crops and plants. Land that has been abandoned to nature will then be able to bloom again, providing much needed food for the poorer countries of the world.

4. Which of the following statements about Flowers and Yeo is true?

A. They are students at Sussex University.  B. They are rice breeders.

5. Which of the following is NOT mentioned as a cause of the problem discussed in the passage?

A. Natural barriers to sea water have been destroyed.

B. The water table has gone down after droughts.

C. Sea level has been continuously rising.

D. Evaporation of water leaves salt behind.

6. The word "affect" in Paragraph 5 could be best replaced by________.

A. influence               B. effect               C. stop                    D. present

7. The attitude of the author towards the research project is________.

A. positive                B. negative            C. suspicious             D. indifferent

属于不健康的行为是（）

A.饮酒

B.定期体检

C.静坐生活方式

D.跑步

E.吃甜食