IV. Write the correct form of the words in brackets. 16. When too many people live in a small place, __________ can become very difficult. (LIVE) 17. He is a __________ student because he goes to class every day. (REGULARLY) regular 18. Coal will be __________ by another renewable source of energy in the future. (REPLACE) 19. How many __________ are there in the program tonight? (PERFORM) 20. A man in a silver sports car __________ into a lady in a big blue truck in the middle of the intersection yesterday. (CRASH)