Đốt 1 thể tích hidrocacbon thuộc loại Ankan cần 5 thể tích Oxi. Xác định công thức phân tử các hidrocacbon đó. Biết rằng các thể tích khí đều ở cùng nhiệt độ và áp suất.

Chuyển câu chủ động sang câu bị động:

1when does he usually do his homwork?

2Someone saw him pick up the gun.

3He like people to call him"sir".

4The Prime Minister is making a speech at the moment.

5You were wearing your new hat when i met you yesterday.

6Mary willsee her friends off at the station.

7You can't wash this dress.You must dry it.

8Someone washes the towels in the hotel everyday.

9They have to pull down that building.

10They have decorated their house recently.

11We should clean our teeth twice a day.

12People say that he is handsome.