Man is a land animal,but he is also closely tied to the sea.Throughout history the sea has served the needs of man.The sea has provided man with food and a convenient way to travel to many parts of the world.Today,nearly two-thirds of the world's population live within 80 kilometers of the sea coast.

In the modern technological world,the sea offers many resources to help mankind survive. Resources on land are beginning to be used up.The sea,however,still can be hoped to supply many of man's needs.

The list of riches of the sea yet to be developed by man's technology is impressive.Oil and gas explorations have been carried out for nearly 30 years.Valuable amounts of minerals exist on the ocean floor ready to be mined.

Fish farming promises to be a good way to produce large quantities of food.The culture of fish and shellfish is an ancient skill practiced in the past mainly by Oriental people.

Besides oil and gas,the sea may offer new sources of energy.Experts believe that the warm temperature of the ocean can be used in a way similar to the steam in a steamship.Ocean currents and waves offer possible use as a source of energy.

Technology is enabling man to explore ever more deeply under the sea.The development of strong,new materials has made this possible.

The technology to harvest the sea continues to improve.Experts believe that by the year 2050 the problems that prevent us from exploiting fully the food,minerals,and energy sources of the sea will be largely solved.

1.What is the beat title for the passage?

A.Needs of Man.

B.Sea Harvest and Food

C.Sea and Sources of Energy

D.Sea Exploring Technology.

2.It can be inferred from the passage that ______.

A.man hasn't completely made use of the riches of the sea

B.technology for exploring the sea has been solved

C.harvesting rice in the sea will be made possible

D.in the near future man can live on the ocean floor

3.Why does the author mention a steamship in paragraph 5?

A.To illustrate that man can make use of sources of energy from the sea.

B.To show that a steamship is better than other kinds of ships.

C.To argue that man should use steamships.

D.To indicate that it is warmer in the ocean than on land.

4.According to the author,technology is important because ______.

A.resources on land are running short in ten years

B.man can use it to explore the deeper sea

C.it is a lot of fun diving into the sea

D.ancient people used it to explore the sea

5.According to the author,when will the problems to explore the deeper sea largely be solved?

A.In the next generation.

B.At the end of the 20th century.

C.In the near future.

D.By the middle of the 21st century.