资料题：The lowest grade allowed for eggs is（  ）。 

The origin of the almighty dollar is in what is now the Czech Republic.In 1519, a silver mine near the town of Joachimstal (literally" Joachim's valley," from the German Tal, meaning valley) began minting(制造) a silver coin called, unimaginatively, the Joachimstaler.The coin, which was circulated widely, became better known by its clipped form, the taler In Dutch and Low German, the initial consonant softened to become daler English adopted this form,eventually changing its spelling to the modem dollar.In the American colonies, there was no standard currency.The coin that was in widest use was the Spanish Peso, known also as" Pieces of Eight" because it could be divided into eight pie- like pieces.The English colonists informally assigned the name dollar to this coin.In 1785,when the Continental Congress established U.S.currency, they adopted dollar as name for the standard unit of currency, at the suggestion of Govemeur Morris and Thomas Jefferson, because the term was widely known and was not associated with any for of official English currency.(Jefferson also coined the term disme, from the French dixieme, for a tenth of a dollar.Pronounced deem, it eventually became dime.)The origin of the $ sign has several folkloric stories attached.One says that Thomas Jefferson invented it, perhaps as a sort of monogram for TS.Jefferson was the first to use the symbol in relation to the U.S.dollar, but this story is fanciful.Another Bays that originally it was U superimposed over an S, for U.S.of course.Eventually the base of the U eroded due to poor printing technology, leaving an S with two lines through it.Another says that it is a variant of a figure eight that appeared on the Spanish Peso, standing for the pieces of eight.This last is close to the truth, but not quite there.The Spanish royal family used on its escutcheon(饰有纹章的盾), two pillars (representing the Pillars of Hercules in Gibraltar and Morocco) crossed by an unfurled banner reading“Plus Ultra." This symbol appeared on the Peso, and looked much like the modem $ sign.It was adopted as a symbol for the Peso in the American colonies, and was transferred to the dollar.The U.S.was the first nation to adopt an official currency named the dollar.In 1797, the Bank of England began minting"dollar" coins as bank - issued currency.Other nations that have adopted the name dollar for their currency have done 8o in emulation of either the U.S.or this short - lived Bank of England practice.