Teeth have been a part of animals almost from the beginning of animal life. The first

animals to have teeth were fish. These sea creatures lived millions of years ago. They had many finely pointed teeth for grabbing food from the water. They were distant cousins of today’s sharks.The teeth of animals help them do certain jobs or eat certain kinds of foods. Elephants have two large teeth, called tusks, which they use for digging up plants or for fighting. Lions and tigers have long, sharp teeth for tearing apart other animals. Those of horses and cows are short and flat. They are used for grinding plants.People have three main kinds of teeth. They have teeth that cut, teeth that tear, and teeth that grind. When biting into a piece of fruit, people use their cutting teeth. When pulling a piece of meat from a bone, they use their tearing teeth. When nibbling on a fresh carrot, they use their grinding teeth.Every person grows two sets of teeth. The first set often begins to appear when a baby is about six months old. It lasts until the child is about six years old. Then the baby teeth fall out and the second teeth come in. This second set must last for the rest of a person’s life.It is important for people to take care of their teeth. They must eat the right foods. They should brush their teeth properly. Teeth should be checked twice a year by a dentist.

1.Fish have many () teeth for () food.

A.noticeable, catching

B.visible, grasping

C.sharp, snatching

D.fine, catching

2.Which of the following statements about teeth is true？()

A.Elephants have three large tusks

B.Teeth of horses and cows are short and sharp

C.The first set of teeth of a person often begins to appear when he is about six years

D.Sea creatures were the first animals having teeth

3.The word “nibble” in the third paragraph bears the meaning of ().

A.eating with small repeated bits

B.showing slight interest in something

C.taking hold of with a sudden rough movement

D.crushing into small pieces or into powder

4.From this passage we can draw a conclusion that ().

A.all the teeth have the same function

B.animals don’t try to protect their teeth

C.teeth are important both for human and animals

D.we should care our teeth and often have them checked

5.It is a piece of writing about ().

A.botany

B.animals

C.popular science

D.dentistry