What kind of hair do you have? Is it curly or straight? Some of us are born with straight hair．Some are born with curly hair．Do you know why?

A number of things decide the way our hair is．Here are some of them．

    The first thing is the follicles（毛囊）．A hair has two parts：the shaft（毛干），which is the part you see，and the follicle，which is hidden under the skin．The curly-haired have flat follicles．Those with straight hair have round follicles．

    Second，how our hair looks is connected with the hair bulb（发根）．The hair bulb is the area from which the shaft grows．The way the bulb sits in the follicle can affect the hair, too．

    The way the cells（细胞）of the hair are arranged（组合）in each shaft can also affect the look of the hair．These cells can be arranged in many ways，and result in different looks of hair．

Lots of people try to change the look of their hair．They use curling irons（烫发器）to make the hair curly or chemicals to make it straight．These methods are only effective（有效的）for a short time．As hair grows and time goes on，hair returns to normal．

1．How many parts does a hair have? What are they?

2．Why can't we see the follicle?

3．What kind of follicles do the people with straight hair have?

4．What can always affect the look of the hair?

5．How can people change the look of the hair for a short time?