16. Daisy has three brothers. All of them are teachers.
⇨ Daisy ….has three brothers, all of whom are teachers..……
17. They open the shop at six o’clock.
⇨ The shop …is opened at six o'clock…………
18. A good way of keeping fit is to swim everyday.                                                                     
⇨ Swimming …every day is good way to keeping fit…………
19. They couldn’t climb up the mountain because of the storm.

⇨ The storm prevented them…from climbing up the mountain.…
20. She was seriously ill but she enjoyed life very much.
⇨ Even though....she was seriously ill, she enjoyed life very much...... 

16. Daisyy has three brothers who are teachers.

17. The shop is opened at six o'clock.

18. Swimming everyday is a good way of keeping fit.

19. The storm prevented them from climbing up the mountain.

20. Even though she was seriously ill, she enjoyed life very much.