How much do you know about Left 4 Dead?

Do you really think that your pro at Left 4 Dead then take this quiz to find out how

1 how many PLAYABLE characters are there?
2 When you see/hear a witch you...?
3 What is the most annoying infected?
4 What is Nigel?
5 What does a Boomer do?
6 Name the 4 survivors
7 you are surounded you do..?