To the dilemma expressed in the title, Phillips answers ""pull the plug,"" and to the anxious traveler who writes ""Is there any surefire way to prevent a rhinoceros from charging,"" he advises ""I suggest you take away its credit card."" More-or-less disguised as Q-and-A advice, this has a section on grammar and usage (""Life in Prison"" is a phrase to some people, a sentence to others) and others on science (""A frog has more lives than a cat because a frog croaks every night""), geography (""Ireland must be the richest country in the world because her capital has been Dublin for hundreds of years""), careers (""Should I become an archaeologist? No, because your career will soon be in ruins""), history (""Where did Richard III keep his armies? Up his sleevies""), even the odd elephant joke. As packaged, it's a brighter than average riddle collection--or maybe it just looks that way with Stevenson's witty cartoons.