Giúp mk mấy bài này đi ạ

15. Although they are old, they worked very hard.

16. Although he was tired, he agreed to play tennis.

17. Although it was hot in the afternoon, we decided not to go for a swim.

18. In spite of the cloudy sky, we took many pictures.

19. In spite of the hot weather, they went jogging in the park.

20. In spite of the heavy traffic, we got there in time.

21. In spite of the heavy snow, all the trains were on time.

Chúc bạn học tốt !