1. Tom said; ''I am a student''

=> Tom said that he was a student

2. The player kicked the ball into the goal

=> The ball was kicked into the goal by the player

3. Shall I sit here?

=> Do you mind if I sit here ?

4. It is a contest in which participants have to cook rice

=> It's a rice-cooking contest

5. People play football all over the world

=> Football is played all over the world

P/S : Good Luck