giúp em với ạ , em cảm ơn đề : chuyển thành because / because of

12. John succeeded in his exam because of his hard and methodical work.

13. Margaret stayed home because of her mother's sickness.

14. All the teachers love him because of his good conduct.

15. I couldn't read the letter because of its darkness.

16. We stopped our car because of the red traffic lights.

17. The plane couldn't take off because of the bad weather.