In some developed countries, larger population is ______________ in their big cities.

A．approved         B．gathered          C．concentrated       D．fixed

In some developed countries, larger population is ______________ in their big cities.

Besides providing a perfect environment for sea plants and animals to live in, seawater has other values, one of which is that it constantly moves, and its movements produce energy.
The most obvious movements are the waves and the tides. Winds cause the waves, and the gravitational pull of the moon and the sun causes the tides. In places like the Bay of Fundy in Canada, the difference between the high and low tide level can be as much as 40 feet.
France and Britain are now trying to use energy in the tides to produce electricity. Waves can produce electricity and some experiments are taking place to learn more about this. One of the most encouraging areas of research uses the difference between the temperature of seawater at the surface and deep down to produce electricity. 
【小题1】Waves and tides are caused by ________ .

Americans who volunteer for the Peace Corps get a chance to help improve lives in developing countries. They also get a chance to learn more about the world, and about themselves. This week this program is celebrating its 50th anniversary.

President John Kennedy established the Peace Corps soon after he took office in 1961. It was the time of the Cold War between the United States and the Soviet Union. The new program gave Americans a chance to answer the call to service that the president made in his inaugural(就职的)speech. “Ask not what your country can do for you,” he said. “Ask what you can do for your country.” Kennedy told Peace Corps volunteers that America’s image in the countries where they were going would depend largely on them.

On August 30th, 1961, the first group of 51 Peace Corps volunteers arrived in Accra, Ghana, to serve as teachers. They had agreed to work for almost no pay. They would spend two years in Ghana helping its people and learning the reality of life in a developing country. Most of the volunteers had just completed college. About half of them taught English or health care. In the 50 years since then, more than 200，000 Americans have served as Peace Corps volunteers. They have worked in 139 countries.

The Peace Corps is a government agency that was created to promote world peace and friendship. There are three goals: First, to help the people of interested countries in meeting their need for trained men and women. Second, to help promote a better understanding of Americans on the part of the people served. And, third. to help promote a better understanding of other people on the part of Americans.

Today, the Peace Corps has more than 8,000 volunteers and trainees in 77 countries. They work in agriculture, economic development, education, the environment and health care. Some work in programs related to youth development.

Sixty percent of current Peace Corps volunteers are women. The average age of a volunteer is 28. But the ages of Peace Corps volunteers range from 18 to 86. Some Americans join the Peace Corps after they retire. Today seven percent of volunteers are over the age of 50. And 19 percent are members of minority groups.

1.Volunteers for the Peace Corps can _______.

A．improve their abilities by learning in some developed countries

B．travel to many foreign countries to learn more about the world

C．have an opportunity to help all the people in developing countries

D．contribute to lives in developing countries and develop themselves

2.Which of the following is TRUE according to the text?

A．Volunteers served as teachers to work for no pay in Accra, Ghana.

B．Kennedy established the Peace Corps before he took office in 1961.

C．Most of the volunteers of the first group had just graduated from college.

D．America’s image in the foreign countries depends completely on volunteers.

3.The fourth paragraph is mainly about _______.

A．what the Peace Corps is and its steps

B．why the Peace Corps was created and what are its goals

C．what role the Peace Corps play in daily life

D．How the Peace Corps was created and its aims

4.According to the text, volunteers and trainees assist in the following aspects EXCEPT _______.

A．industry           B．environment       C．education         D．health care

5.What can we learn from the last paragraph?

A．Most of the volunteers for the Peace Corps are women.

B．Few minority groups joined the Peace Corps.

C．Half of the retired volunteers joined the Peace Corps.

D．People of different ages take an active part in the Peace Corps.

World Health Day is celebrated on 7 April to mark the anniversary of the founding of WHO in 1948. Each year a theme is selected for World Health Day that highlights a priority area of public health concern in the world. 
The theme for 2013 is high blood pressure. High blood pressure increases the risk of heart attacks, strokes(中风). If left uncontrolled, high blood pressure can also cause blindness, irregularities of the heartbeat and heart failure. The risk of developing these complications is higher in the presence of other risk factors such as diabetes(糖尿病). One in three adults worldwide has high blood pressure and this increases with age, from 1 in 10 people in their 20s and 30s to 5 in 10 people in their 50s. High blood pressure is most common in some low-income countries in Africa, with over 40% of adults in many African countries thought to be affected.
However, high blood pressure is both preventable and treatable. In some developed countries, prevention and treatment of it has brought about a reduction in deaths from heart disease. The risk of developing high blood pressure can be reduced by: reducing salt intake; eating a balanced diet; avoiding harmful use of alcohol; taking regular physical activity; keeping a healthy body weight; and avoiding tobacco use.
The final and most important goal of World Health Day 2013 is to reduce heart attacks and strokes, which includes as follows:
1.to raise awareness of the causes and consequences of high blood pressure;
2.to provide information on how to prevent high blood pressure
3.to encourage adults to check their blood pressure and to follow the advice of health-care professionals.
【小题1】High blood pressure can cause medical problems like_____.