`->` Was there any community service in your neighborhood last summer?

Was there any community service in your neighborhood last summer?

Để nguyên một cặp rành rành, cặp ở đây là đôi

Đôi thêm sắc là thành đối (đối xứng song hành)

Thay sắc thành nặng là đội (mang trên đầu)

Đổi sắc thành huyền là đồi (gò đất màu xanh xanh)

Vậy từ để nguyên là từ đôi.

gặp gỡ là hoạt động nhé!

hoạt động nhé

The roof of the building was held up by a row of thick stone columns.

Tuần trước , thầy giáo nói em và các bạn vẽ ước mơ của em . Lúc đầu em còn không biết vẽ , lúc sau , Nga đã dạy em vẽ và bức tranh đã được hoàn thiện xong . Em cảm thấy rất vui . 

Thế này được khum ?

cũng đc á

12.There are four seasons in our country.

12. There are four seasons in our country.

Dịch: Đất nước chúng tôi có bốn mùa.

I want to do something exciting.

turn the following sentences into negative sentences and questions

1.(+)he is listening to music

(-)____He isn't listening to music_________________________________________________

(?)__Is he listening to music?___________________________________________________

2.(+)they are wearing jeans

(-)_____They aren't wearing jeans________________________________________________

(?)_______Are they wearing jeans?______________________________________________

3(+)Elizabeth is sweeping the floor.

(-)____Elizabeth isn't sweeping the floor_________________________________________________

(?)____Is Elizabeth sweeping the floor?_________________________________________________

4(+)It is raining cats and dogs today

(-)____It isn't raining cats and dogs today_________________________________________________

(?)______Is it raining cats and dogs today?_______________________________________________

5(+) my family is going to the park right now

(Câu này bạn bổ sung thêm chữ now nữa nha)

(-)_____My family isn't going to the park right now_______________________________________________

(?)_____Is your family going to the park right now?________________________________________________

6(+)the children are listening to their teacher

(-)____The children aren't listening to their teacher_________________________________________________

(?)______Are the children listening to their teacher_______________________________________________

7(+)a man is selling ice-cream in the park

(-)______A man isn't selling ice-cream in the park_______________________________________________

(?)______Is a man selling ice-cream in the park?_______________________________________________

8(+) the girls are dancing

(-)______The girls aren't dancing_______________________________________________

(?)____Are the girls dancing?_________________________________________________

9(+)pupils are talking to each other

(-)____Pupils aren't talking to each other_________________________________________________

(?)____Are pupils talking to each other?_________________________________________________

10(+)I am doing the washing-up

(-)______I am not doing the washing-up_______________________________________________

(?)____Are you doing the washing up?_________________________________________________

a, \(CH_4+2O_2\underrightarrow{t^o}CO_2+2H_2O\)

\(C_2H_4+3O_2\underrightarrow{t^o}2CO_2+2H_2O\)

b, Ta có: n_CH4 + n_C2H4 = 0,5 (1)

Theo PT: \(n_{CO_2}=n_{CH_4}+2n_{C_2H_4}=\dfrac{30,8}{44}=0,7\left(mol\right)\left(2\right)\)

Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}n_{CH_4}=0,3\left(mol\right)\\n_{C_2H_4}=0,2\left(mol\right)\end{matrix}\right.\)

c, \(C_2H_4+Br_2\rightarrow C_2H_4Br_2\)

_____0,2____0,2 (mol)

⇒ m_Br2 = 0,2.160 = 32 (g)

d, \(d_{Y/H_2}=\dfrac{\dfrac{0,3.16+0,2.28}{0,5}}{2}=10,4\)