Rewrite the sentences so that their meaning doesn't change

Giải giúp mình nhé các bạn:
I. Rewrite the sentences so that their meaning doesn't change:(1.0point)
1.Mary was sick, so she could not go to school.
->because...............................................................
2.I met him 3 years ago
->I have....................................................................
3.Lan went out because she finished her homework. (so)
->Lan...............................................................................
4. He is interested in doing morning exercise.
->He................................................................