Height is just one of the features your genes (基因) 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 them 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.
It’s natural that you’re wondering how fast you should grow. There’s no perfect or right answer. Generally speaking, kids grow about 6 cm 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. 2 cm here and 3 cm there make a little difference to the height you’re at now. How have you been growing up to this height？What other changes may your body be going through？
Don’t be amazed 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 after your body starts to show the first changes of puberty.
If you want to know how tall you should grow, _______.

A．you should have enough exercise

B．you can ask doctors for help

C．you should take some special medicine

D．you can record your growth during puberty

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

This passage is mainly about ______.

A．how the genes work in your body

B．how your parents’ height influence you

C．how you look like your parents

D．how you grow to a certain height

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

Which is NOT mentioned in the passage？

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

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

C．The features showing the first changes of puberty between boys and girls are different.

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