11. Harry had to stay in hospital because of his broken leg.
-> Because
12. Jim had to give up jogging because he had sprained his ankle
severely.
-> Because of .
13. The water in most rivers is unsafe to drink because of its pollution.
->Because
14. We all have received the best of everything because our parents are
generous.
->Because of .
15. John has to sit in the front row in class because of his poor eyesight.
-> Because

16. Piranhas can devour an entire cow in several minutes because
their teeth are extremely sharp.
-> Because of .
17. Most students couldn't do the final exam because of its
difficulty
->Because
18. Sarah will not walk across a bridge because she's afraid of
height.
-> Because of .
19. We postponed our trip because of the bad driving conditions.
-> Because