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

Câu 2:

a, Gọi CTPT cần tìm là C_nH_2n

⇒ 14n = 42

⇒ n = 3

Vậy: CTPT cần tìm là C₃H₆.

b, Ta có: \(n_{C_3H_6}=\dfrac{3,7185}{24,79}=0,15\left(mol\right)\)

PT: \(2C_3H_6+9O_2\underrightarrow{t^o}6CO_2+6H_2O\)

____0,15__0,675___0,45 (mol)

\(\Rightarrow V_{O_2}=0,675.24,79=16,73325\left(l\right)\)

c, \(CO_2+Ca\left(OH\right)_2\rightarrow CaCO_3+H_2O\)

____0,45________________0,45 (mol)

⇒ m_CaCO3 = 0,45.100 = 45 (g)

There is a beautiful garden with many tall trees and flowers at my school

Từ giữ nguyên là từ báo. Tờ báo bố đọc hằng ngày.

Thay sắc bằng huyền ta được từ bào: (cái bào dùng để bào gỗ của thợ mộc)

Vậy từ để nguyên là từ báo.

Theo bài ta có: n_CO2=2,24;22,4=0,1 (mol)

PTHH: CO2 + Ca(OH)2 --> CaCO3 + H2O

            0,1                              0,1                  (mol)

--> m_KT=100.0,1=10(g)

`1.` We enjoyed the party, but there wasn't anything to eat.
`2.` Macy had an argument with her best friend yesterday.
`3. `We eat meat, but we 've been to vegetarian restaurants lots of times.
`4.` Have you ever cooked a meal for your friends?
`5. ` It was Mum's birthday on Sunday and we went out to a restaurant.
`6. `I 've never ordered pizza online