A:CO2,H2O
B:CO2、CH4
C:Cl2、CS2
D:NH3、HCl
No. 1 Middle School
Don't run in the hallways
Don't bring food into the classroom.
Don't listen to music in class.
You have to wear a uniform.
No. 2 Middle School
Don't bring food into the classroom
Don't wear a hat in class.
Don't go into the classroom without the teacher.
No. 3 Middle School
Don't listen to music in the classroom.
Don't run in the hallways.
You have to wear sports shoes for gym class.