Page 29 - 新思维科学学生用书6 样章

1 The human body

Growing and developing

When you were born you were

very small. You couldn’t walk
or talk or do anything for

yourself. Now you are much

bigger and can do many
things for yourself.

Throughout your childhood
you continue to grow and

develop. You not only grow

taller and heavier, but your
body changes in other ways

too. Some of the changes

mean that you are becoming
an adult and will be able to reproduce.

This stage in your life is called puberty.

Puberty starts at different ages in boys and girls. In boys, puberty usually starts when
they are about 13 years old. In girls, puberty often happens from the age of 11. The

changes that happen during puberty don’t happen all at once, but in stages. These
changes are caused by chemicals in your body called hormones.

The first change you will notice is that you grow very fast. Boys can easily grow 10 cm in

a year. Girls can grow up to 12 cm in a year as puberty starts.
One of the other changes you will notice is that your body grows more hair. In boys,

hair begins to grow on the face, armpits and other parts of the body. In girls, hair
begins to grow in the armpits and other parts of the body.

Your skin can also get oily. Many boys and girls get pimples during puberty.

A boy’s shoulders and chest will get broader as his body muscles develop. His voice
will change and become deeper.

A girl’s hips will get wider and she will start to develop breasts. Her voice will also

become a little deeper.

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