A. altitude B. familiarity C. cube D. total A. blindfold B. nature C. ring back D. participant A. severe B. abrupt C. congestion D. youth A. carefully B. get on with C. lonely D. valid A. dispute B. yuan C. amphibious D. sail A. effect B. flap C. greengrocer D. sort out A. green pepper B. tetrahedron C. precaution D. back to back A. storybook B. abstract C. occasionally D. professional A. quantities of B. set out C. seashore D. none A. patent B. tip C. keep fit D. decoration