I think question #9 is a bit confusing. There's no answer that really makes sense. You're asking for a synonym for the word "subterranean", which means "existing, occurring, or done under the earth's surface" (Oxford Dictionaries). According to the quiz, the correct answer is "ulterior"...but the definition of that word is "existing beyond what is obvious or admitted; intentionally hidden". The most commonly used synonym for "subterranean" would be "underground".more »
