One of my hobbies is collecting stamps, especially foreign stamps. My hobby started when I was nine years old. Firstly, I have just collected local stamps. But then, I loved it and I collected more foreign stamps. Now, I have 263 local stamps and 120 foreign stamps. I usually see them in my free time. They look so beautiful and great. I think it is good hobby, I will never stop it.

1. book

2. look

3. full

4. good

5. woman

6. should

7. neighbourhood

8. pool

9. cook

10. put

11. understood

12. cushion

13. cuckoo

14. football

15. wool

16. childhood

17. could

18. sugar

19. butcher

20. would

Ta có:

\(\widehat{bIa}+\widehat{aIS}=60^o\)

\(\widehat{aIS}+\widehat{SIt}=90^o\)

\(\Rightarrow\widehat{SIt}-\widehat{bIa}=30^o\)

Ta lại có: \(\widehat{SIt}=\)\(\widehat{tIb'}=\dfrac{180^o-\widehat{bIS}}{2}=\dfrac{180^o-60^o}{2}=60^o\)

\(\Rightarrow\widehat{bIa}=60^o-30^o=30^o\)

Vậy phải đặt gương phẳng hợp với mặt phẳng ngang 1 góc là \(30^o\)

Tại sao dạo giờ em không đổi được avatar vậy thầy?

@phynit

\(=a^2+b^2+c^2-2ab-2bc+2ac\)

a)550m

b)39,6km

1 . My class is in the second floor .

=> on

2 . He is watches the cartoon in the room now .

=> watching

3 . What does she do yesterday evening ?

=> did

4 . What about go to the zoo today ?

=> going

5 . How many peoples are there in your room . giúp mình friends

=> people

you talk more than you work . The teacher wants you to work more than to talk

-> The teacer wish you worked more than you talked.

the teacher wants you to be more studious

- The teacher wish you were more studious