1.c

2.f

3.h

4.a

5.d

6.g

7.e

8.b

gọi A = 99...99 (n chữ số 9)

A = 99..90 (n- 1 chữ số 9) + 9

99..90 chia hết cho 9 và 5 nên chia hết cho 45

vậy số tự nhiên nhỏ nhất + với A để chia hết cho 45 chính bằng số tự nhiên nhỏ cộng với 9 để chia hết cho 45 

số đó là: 45 - 9 = 36

ĐS: 36

1. I want lie on the couch in front of the TV now. (want to lie)

2. People are living longer so there are much elderly people. (much => more)

3. There is an interesting movie at on TV now. (bỏ at)

4. Minh often practices the guitar at his free time. (at => in)

peter gavelis  few apples from her garden

she has a little self-confidence she lots of trouble talking to new people

it is a great pity but  hospital has littlemedicine they canot help many people 

I have got a few cakes to give away would you like one

sửa lỗi

nam usually  goes to the dancing group at  saturday night (at => on)

yesterday , I am went to school late  so do I (bỏ am)

in geographic we study past and present event in Vietnam and around the world (geographic => history)

we can learn much thing from books (much => many)

I am tired of waiting for buses I am going there in foot (in => on)

1.we learn how to sing songs in Music class 

=> What do we learn in Music class.

2.My father is jogging in the park .

=> Where is your father jogging?

3.lan is studying physics at class now. 

=> What is Lan studying at class now?

1.a. attend   b.plane     c.celebration    d.organization 

2.a.comic    b.volunteer  c.model         d.together

3.a.scout     b.group        c.couch         d.house

4.a.teenager  b.together   c.guitar       d.game

A magazine survey of 13 years old show what American teenagers like to do in their free time . Here are some most popular activities.

Eating in fast food restaurant is one of their favorite. Some young people attend youth organizations such as scouts and guides.

Many of them learn to play a musical. instrument.

Most of the young enjoy going shopping. Watching television is also their enjoyment. Some like to go to the movie while others listen to music. Several of them collect things such as stamps or coins. A few make models of things such as cars or planes.

There are many volunteers who help old people withtheir shopping or cleaning. Now teenagers are doing more community service.