Hi, I’m your tooth. I’ve been asked to represent the rest of your teeth. We need your help. We are feeling a bit neglected and we need your help.
First, let me tell you a little about us. You weren’t born with our predecessors(前辈),the baby teeth.They developed when you were about six or seven months old. Then they were all ready to chew.You went from milk to real food in no time thanks to your twenty primary teeth. Finally, they loosened and fell out, one at a time, probably about the time you were six or seven years old.
Then we came into your life. We are your permanent teeth, all twenty-eight of us. Some people may even have thirty-two depending on those wisdom teeth in the back. Sometimes they come in, and sometimes they cause trouble.You just never know about them. Many times wisdom teeth come in wrong directions and have to be pulled out. Some people don’t even have them at all!
On a more personal note, I am an tooth in the front of your mouth, and you have seven more just like me here. We do the biting on those chocolate chip cookies you like so much. Next to us are four sharp teeth, two on either side. Their job is to tear food; pizza is a good one for them. Behind them are eight premolars(小臼齿) and eight to twelve molars, depending on those wisdom teeth. The molars do the majority of the work chewing and breaking or crushing the food that you eat. They do a great job on those carrots you like so much!
To keep us healthy,we need to be brushed twice a day.Instead of a quick brushing,brush us for at least two to three minutes.If we don’t get cleaned,you could lose some of us.That’s definitely not what you want,is it?
From the passage we can infer that ___.

A．the teeth’s main job is to digest the food we eat

B．we should take good care of our teeth

C．some children are born with several baby teeth

D．primary teech fall out when we are six or seven months old

How many teeth does a four-year-old boy usually have?

A．Twenty

B．Twenty-four

C．Twenty-eight

D．Thirty-two

Wisdom teeth are sometimes pulled out mainly because ___.

A．they are useless

B．there are too many of them

C．they come in wrong places

D．they grow in wrong direction

The speaker “I” in this passage is ___.

A．a wisdom tooth

B．a baby tooth

C．a sharp tooth

D．a permanent tooth