Problem: Which is the smallest borough of New York?
Answer: manhattan

Problem: In which city did the United Nations Conference on Environment and Development, known informally as The Earth Summit, take place in June 1992?
Answer: rio de janeiro

Problem: Only one man since Donald Budge has won the tennis Grand Slam, achieving this feat twice, who is he?
Answer: rod laver

Problem: Which web application on Yahoo! that translates text between different languages is named after a fictional animal used for a similar purpose in The Hitchhiker's Guide to the Galaxy?
Answer:
babel fish