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 decided 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(怀疑) 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.

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.

56. The underlined word “puberty” means________.

A. when your body starts changing and becoming more grown up

B. when your body starts growing

C. when your body grows slowly

D. when your body stops growing

57. Which is NOT mentioned in the passage?

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

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

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

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

58. 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

59. This passage is mainly about ________________.

A. how the genes work in your body.

B. how you grow to a certain height

C. why you look like your parents

D. when is the time you grow fast

阅读理解
There are 45 students in our class. I have made a survey, 36 students say they like to exercise. Most boys play basketball together twice a week. But girls think basketball is difficult for them, they’d like to play volleyball together twice a week. My friend, Tony, is good at running. He runs fastest in our class. He runs for 30 minutes on the playground every evening before he goes to bed. Is it interesting? Gray is good at swimming. He goes to the swimming club three times a month in winter, and three times a week in summer. So he is pretty healthy. Some of my classmates have good eating habits. They eat both meat and vegetables. 70% of them drink milk every day. 15 students say they drink milk three or four times a week. But some students like to eat junk food, especially Sally. What’s worse is that she doesn’t like to exercise, so she is very fat. She always says “ I’m going to lose weight(减肥) tomorrow.”
【小题1】 How often do most boys play basketball?

阅读理解

There are 45 students in our class. I have made a survey, 36 students say they like to exercise. Most boys play basketball together twice a week. But girls think basketball is difficult for them, they’d like to play volleyball together twice a week. My friend, Tony, is good at running. He runs fastest in our class. He runs for 30 minutes on the playground every evening before he goes to bed. Is it interesting? Gray is good at swimming. He goes to the swimming club three times a month in winter, and three times a week in summer. So he is pretty healthy. Some of my classmates have good eating habits. They eat both meat and vegetables. 70% of them drink milk every day. 15 students say they drink milk three or four times a week. But some students like to eat junk food, especially Sally. What’s worse is that she doesn’t like to exercise, so she is very fat. She always says “ I’m going to lose weight(减肥) tomorrow.”

1. How often do most boys play basketball?

2. Why do the girls dislike to play basketball?

3. When does Tony often run for 30 minutes?

4. How often does Gray swim in winter?

5. Why is Sally so fat?