7．The key to preventing you from falling into a state of sub-health is that you should ___.

A．work hard B．sleep more

C．form good living habits D．take more medicine

8．As for food, experts suggest that ___.

A．we should never eat meat B．we should have a variety of food

C．we should eat less than usual D．we should have meals without salt and sugar

C

　About 97% of the world's water is salty and is found in our oceans and seas. But, as we can't drink sea water, how can it be important?

　　Every part of our seas and oceans contains an amazing number of animals and fish that live at different ocean depths. Most of the different species of animals and fish depend on simple plants for their food. These simple plants called algae (海藻) drift near the surface of the ocean and use sunlight to turn carbon dioxide and water into food and oxygen. In fact, algae produces over half of the oxygen people breathe. How important sea water is!

　　Each plant or animal in our seas and oceans is an important link in a food chain. The algae are eaten in large amounts by microscopic animals, which are in turn consumed by larger animals. These food chains are delicately balanced.

　　The bad news about the food chains in the oceans is that they are under threat because of man. People once thought that the oceans were so big that it didn't matter if we dumped rubbish into them or caught huge quantities of fish and whales for food. But we now know this is not true and fish stocks in the oceans have started to drop.

Thankfully, the world is taking steps to protect the future of our oceans by introducing international agreements to protect marine habitats. Most countries have introduced fishing restrictions to protect fish stocks in the oceans and new techniques are being pioneered to cope with pollution. Finally, the importance of protecting oceans is being made known to more people. This is just the beginning of a long process to protect the oceans for our future. We depend on the oceans for fish which are an important part of the human diet. How important sea water is!

9. People used to think that the rubbish thrown into the sea ________.

A. would change the balance of the food chain B. wouldn't be broken down in the sea

C. wouldn't harm the fish in the sea D. wouldn't do much harm to the sea

10. From the passage, we learn that _________.

A. most fish and sea animals live at the surface of the seas

B. it is very difficult to break the balance of a food chain

C. excessive fishing has caused the decrease in fish stock

D. it won't be long before the problems concerning oceans will be solved

11. Which of the following is NOT a way being used to protect oceans?

A. . Raising people's awareness of the need to protect oceans.

B. Forbidding fishing to protect fish stocks.

C. The use of international agreements.

D The use of new techniques.

12. What would be the best title of the passage?