***  Sharpen your quizzing muscles with this brilliant new compilation of trivia-based crosswords from the Telegraph!  Boasting 60 puzzles and more than 1500 questions, The Telegraph General Knowledge Crosswords 6 is guaranteed to entertain, relax and enthral you, no matter what your circumstance.   Whether you're a seasoned puzzler or a lover of quizzes, this is the perfect antidote to a busy day or a boring afternoon.