QUESTIONS

Q : At what height would a plane have to be before its sonic boom was not audible on land or at sea? William W. Scott, North Berwick, east Lothian. Q : In comparison to man-made pollution, how does the Hawaiian volcano measure up? M. Stacey, Youlgreave, Derbys. Q : Why do sumo wrestlers hold an annual baby-crying tournament? Lee Walters, Wolverhampton, W. Mids.