là 1 từ mà

từ ghép

Does Harry have to get up early?
We have to get to school before 8.30 am
Jason and Sarah have to wear uniforms.
Do you have to stay at school for lunch? - Yes, I do
We don't have to do homework at the weekend

 

thay n bằng mấy số kia

n= {1;2;3;4;5}

;-;

n= {1;2;3;4;5}

1 ; 2 ; 3 ; 4 ; 5

n∈N hay N*

0 ; 1 ; 2 ; 3 ; 4 ; 5 ; 6 ; 7 ; 8 ; 9 ; 10 ; 11 ; 12 ; 13 ; 14 ; 15 ; 16 ; 17 ; 18 ; 19