Tuổi mẹ là : 

( 47 + 27 )  : 2 = 37 ( tuổi )

Đáp số 37 tuổi

Có \(^{10^{2011}=10...0}\)( 2011 số chữ số 0)

=> \(^{10^{2011}+8=10..08}\)( 2010 số chữ số 0)

Lúc tổng các chữ số trong số 10..08 là 9 chia hết cho 9

=> \(^{10^{2011}+8}\)chia hết cho 9

READING :Read the passage , and do the tasks that follow .

Nick's voice is changing . It is one of the many developments that happen to both girls and boys when they reach puberty : a boy's voice gét deeper than a girls 's.

At puberty , boy's bodies begin producing a lot of the hormone testosterone , which causes in several parts of the body , including the voice . For starters , a boy's larynx , also know as the voice box , grows bigger , which causes your voice to get deeper.

Along with all the other changes in your body , you might notice that your throat area looks a little diferent . For boys wherevihe larynx grows bigger , part of it sticks out in the part of the neck at the front of the throat and forms the Adam's apple . For girls , the larynx also grows bigger but not as much as a boy's . That is why girls don't have Adam's apples.

While your body is getting used to these changes , your voice can be difficult to control . A guy's voice "cracks " or "breaks" because his body is getting used to the changing size of his larynx . Fortunately , the cracking and breaking is only temporary . It usually lasts no longer than a few months.

Generally , a boy's voice will start to change somewhere between the ages of 11 and 15- although it can be earlier or later for some .

Task 1 : Read the text , and identifi whether the statements are true (T) or false (F) .

........... 1 A boy's voice gets deeper than a girl's because the boy reaches puberty.

........... 2 The larynx may be responsible for creating the sound of your voice.

........... 3 When boy's reach puberty , they only change in their voice .

........... 4 Girls don't have Adam's apples because their larynx doesn't grow bigger .

........... 5 We can't see Adam's apples of girls .

........... 6 When boys reach puberty , they can't control their voice .

........... 7 In general , boys don't have the same age of puberty .

........... 8 The changes of voice often last a few months .

Task 2 : Finds words in the passage to match these definitions .

1................................. : (of a sound ) lower.

2................................. : any of the chemical which affects the development of living things.

3................................. : lasting for a short time .

4................................. : a stage when a person develops from a child into an adult.

9 9 9 9 9