All of a sudden bell rings and school is over.

[tufguy]

The film starts with the shot of a teacher teaching the students at school. She is being nice to the kids. All of a sudden bell rings and school is over. Kids leave for a long weekend.

Please check my sentences.

 

[teechar]

Use "the bell" and "the kids."

 

[GoesStation]

Also "a shot" unless you have previously discussed the scene.