Of all the things we eat and drink, water is the most important. Not all people realize this, but it is quite true. The human body can live without food for a long time, but two or three days without water usually result in death.
Many people do not understand how much water the human body needs, but many people do not drink enough, especially in the hot weather. Most people drink when they are thirsty but often need more water after exercises.
65 to 75 percent of the human body is water. Water is important in several different ways. Most peopleneed about five to seven litres (升）of water every day, but we need not drink this amount because a lot comes from the food we have. If we don't have enough water, however, we will feel tired and may become ill. Do you know what the best drink is? Yes, you are right：Cold water!
Fromthe first paragraph, we can draw a conclusion (结论）that __________.

A．water is more important than food

B．water is as important as food

C．water is less important than food

D．both water and food are very important

Do most people drink five litres of water every day? __________

A．Yes, because water is the most important.

B．No, becausewhat we eat contains water.

C．Yes, because we can't live without water.

D．No, because we are not thirsty.

How much water is there in the human body?

A．About three-fourths of the human body is water.

B．Nearly a half of the human body is water.

C．Less than a half of the human body is water.

D．Almost one fourth of the human body is water.

When do we need more water?

A．In cold weather or after exfcrcises.

B．In hot weather or after exercises.

C．Beforebreakfast, lunch and supper.

D．When we feel tired or become ill.

Which of the following is not right?

A．Cold water is the best drink.

B．Few people understand how much water the human body needs.

C．All the people realize water is the most important.

D．When we feel tired or become ill, we never need any water.