Use the correct form of the words in brackets.
13. My new friend is quite (humor) ______. He often makes us laugh.
14. Mr. Bell demonstrated his (invent) ______ at a lot of exhibitions.
15. (Dangerous) ______, the baby is holding a knife in his hand.
16. My mother had (do) ______ everything without equipment.
1 humorous
2 invention
3 Dangerously
4 to do