There are two common explanations for origin of tipping. The Oxford English Dictionary says tip was seventeenth-century underworld slang for “give” ———as in “Tip me your money or your life. ” Opponents of tipping will probably prefer this explanation, since it suggests the practice as originally a form. of robbery. A less reputable, but nonetheless charming explanation is that in Renaissance( 文艺复兴) coffeehouses, boxes were set near the door, into which customers could drop money: These boxes, according to the story, bore the legend “To Insure Promptitude, ” which was ultimately shortened to TIP. Whether it was a serving woman or a boss with his or her eye on depressing wages who first thought up the idea, the story does not say. Tipping became common in England by the middle of the eighteenth century. Because it is ill-suited to a country without an established servant class, it did not catch on in America until after the Civil War, when former slaveholders suddenly found themselves having to pay the help and when new-rich industrialists adopted the European fashion. By the turn of the century, we had made the custom our own, and the American “big tipper ” was on his way. Today, although the lines between bribery(贿赂) and thanks for services remain as vague as ever, tipping has become universal, not least because, in an increasingly uncertain economy, it provides the growing service class with income that is at least as reliable as wages and that is less subject to tax review. Not surprisingly, government officials as among the few die-hards who still question the tipping system. They have a point too. Tippers ’ International Association estimates that U.S. workers get about $5 billion a year in tips. In the seventeenth century, tip was probably a word used by_____. A.lawbreakers B.customers C.waitresses D.coffeehouse bosses Tipping did not become popular in U.S. until after the Civil War because______.A.the country was free of a servant class B.former slaveholders did not want to pay the help C.northern industrialists refused to adopt the European fashion D.tipping was contradictory to the American custom Tipping is universally accepted mainly because_______.A.it is an easy way to make money B.it ensures people a good and prompt service C.it enables the service class to be free from taxes D.it supplies the service class with a sort of reliable income Which of the following words can best describe the government officials ’ attitudes towards the tipping system?A.Positive. B.Negative. C.Doubtful. D.Indifferent. The passage is about_______.A.the origin of tipping B.the practice of tipping in U.S C.the popularity of tipping D.the shaping of the tipping system