FOUR RIDDLES

1. How easy is it to count in binary?
2. What is the only English word that is a plural of a plural?
3. What is the exception to everything?
4. Where do the antelope play?

Answers:

1. It's as easy as 1, 10, 11.
2. OPERAS - the plural of OPERA - which is the plural of OPUS. 
3. The kitchen sink 
4. In Gnu England