M=(-a+b)-(b+c-a)+(c-a) = -a+b-b-c+a+c-a=-a
Vì a là một số nguyên âm nên -a là một số nguyên dương => M=-a>0
Vậy M luôn luôn dương.

tớ biết là 71 rồi nhưng tớ chỉ muốn hỏi cách làm giúp tớ với

there is one mistake in each sentence . Underline and correct the mistake

1. Nam is my classmates . He watches TV every night

2. I think collecting stamps are interesting

3. My dad cooks very good . He loves preparing meals for our family

4. I enjoy to ride my bike to school

5. We usually go in a small lake out of the city at weekends

6. Do you still play football next year ?

7. We like doing fishing because it is relaxing

8. Do you think bird-watching interesting ?

9. I think playing volleyball interest because it is a team game

10. In my opinion , more people played monopoly in the future

GIá trị nhỏ nhất của biểu thức B là 1.

I . Pick out the word which is stressed differently from the other three . Write your answer in the paper test ( 3 points )

1.A happen B. expect C.local D.wander

2.A. Jungle B. volcano C. Surround D. Marine

3.A. Recycle B. Protect C. Instead D. Natural

II . Chooes the word whose stress pattern is different from the others by circling A,B,C or D (1 pt )

1.A. Decide B.prefer C. Listen D.Enjoy

2.A.Middle B.Around C.Friendly D.Country

3.A.Concert B.Teenager C.Comfortable D.Cartoon

4.A.Battle B.decorate C.Delicious D.Grandmother

5.A.Skillful B.Discovery C.Problem D.Popular

6.A.Forest B.Desert C.Building D.Mountain

7.A.Pastimes B.Classroom C.Housework D.Canteen

8.A.Hotel B.Remember C.Repeat D.Classroom

9.A.Dangerous B.Engineer C.Telephone D.Accident

10.A.Visit B.Unload C.Receive D.Correct

IV. Choose the underline word or phrase that is incorrect

1.Tim is at the same age as Hoa

A B C

2.At recess , the students practice/ to play basketball

A B C D

3.Do you know how much /a banana cost ?

A B C D

4.The teacher says Ba will be a fomous artist in one day
A B C D

5.Some boys are playing marble in the school yard at recess

A B C D

6.Some students are playing games as blind man's buff and catch
A B C D

7.Mai leans how to use a computer in her scientific class

A B C D

8.I'd love coming to your birthday but I'am much too busy

A B C D

9.There are less TV programs for teenagers than there are for adults

A B C D

10.People are living longer so there are more and more many old people

A B C D