Height is just one of the thousands of features your genes decide. In fact, because you have two parents, your genes provide you a height that usually lands somewhere between the height of each parent. If both your parents are tall, then most probably you will be tall, too, but if you have questions about how tall you're going to be, ask your doctor if he or she can help you find it out.

But genes don't decide everything. For example, eating an unhealthy diet can keep you from growing to your full potential(潜力). Getting plenty of sleep and enough exercise will help you grow to the expected height.

No doubt you're wondering how fast you should grow. It depends. There's no perfect or right answer. Generally speaking, kids grow about 2 inches (6 centimeters) a year between age 3 and the time when they start puberty (when your body starts changing and becoming more grown up).

Your doctor will know how your growth has been going over the years. Two centimeters here and 2 inches there are not nearly as important as the height you're at now, how you've been growing up to this point, and what other changes your body may be going through.

Don't be scared if you seem to have grown a lot in a very short time. Everyone has a growth spurt（高峰）during puberty. The age for starting puberty is about 10 for girls and about 11 for boys. But it can be earlier or later ----between 7 and 13 for girls and 9 and 15 for boys.

You'll usually begin to notice that you're growing faster about a year or so after your body starts to show the first changes of puberty. 

1.. The Chinese for the word “puberty” is 　　　　　　　　　.

   A. 童年时期          B.婴幼儿时期        C.习惯养成期        D. 生长发育期

2. If you want to know how fast and how tall you should grow, _____.

   A. you should have enough exercise   B. you can ask doctors for help

   C. you should save the environment   D. You can record your growth during puberty

3. This passage is mainly about 　　　　　　　　　.

   A. how the genes work in your body           B. when is the time you grow fast

   C. why you look like your parents                D. how you grow to a certain height 

4. After reading this passage, we can explain 　　　　　　　　　.

   A. how good it is to be a doctor             B. how much sleep time we need

   C. why genes can’t decide everything            D. what healthy diet is

5. Which is NOT mentioned in the passage?

   A. Your height most probably depends on how high your parents are.

   B. Girls’ age for starting puberty is usually earlier than that for boys’.

   C. The time showing the first changes of puberty is never noticed.

   D. You may be scared sometimes when you grow too fast.

Have you ever heard the saying "If you want a friend, be one"? If you want to make friends with others, you should be friendly to them first.

      Here is how one new teacher made friends with the students in her class on the first day of school. As the bell rang, the teacher smiled （微笑） at each student. Then she said in a quiet voice,"Good morning. How nice it is to have all of you in my class this year. I'd like to know each of you. I am sure we will enjoy working together." Her voice was sweet（甜美的） and her look was friendly, so everyone felt happy.

      She told the students her name and wrote it on the blackboard. Then she told them some of the things she liked to do and she hoped to do with them during the year. Then she said to the boys and girls, "Now you know my name and the things I like and I want to know your names and the things you like."

      Could you make friends by doing the same as this teacher did?

      One way of getting to know girls and boys in your class is to find out more about them. People often make friends with those who are the same as them. You play the same games and go on vacations together. It is a good way to make friends.

1.判断正误。The teacher's voice was sweet. 【　　】

2.完成句子。She told the students                          and wrote it on the blackboard.

3.完成句子。One way of getting to know girls and boys in your class is to                           .

4.找主题句。从文中找出一句能概括本文主旨大意的句子。

5.将文中画线句子翻译成汉语。