Đốt cháy hoàn toàn 1 lít hỗn hợp khí gồm C₂H₂ và hidrocacbon X sinh ra 2 lít khí CO₂ và 2 lít hơi H₂O (các thể tích khí và hơi đo ở cùng điều kiện nhiệt độ, áp suất). Công thức phân tử của X là

A. C₂H₄

B. C₂H₆

C. C₃H₈

D. CH₄

I went to the countryside to visit my grandparent.

visited \(\rightarrow\)visit

This is my dream school. It looks like a fish . It will have 24 classes with 1000 students. The class has a board , a air conditioner , 30 desk and 60 chair.

It also has many clubs : volleyball clubs , leader club , football club ... The teachers are very kind and friendly. And the students are all serious and creative.

1. What time does he get up ?

2 . I have breakfast at six twenty.

3 He washes hí face every morning

4 His mother works in a factory.

5 My brother watches television every evening .

6 Mai does her homework every afternoon.

7 I listen to music after school .

8 Ba and Nam play games after school.

50 dm