阅读理解 passage one As the merchant class expanded in the eighteenth century inNorth American Colonies, the silversmith and the coppersmithbusinesses rose to serve it. Only a few silversmiths wereavailable in New York or Boston in the late seventeenth century,but in the eighteenth century they could be found in all majorcolonial cities. No other colonial artisans rivaled the silversmiths’prestige. They handled the most expensive materials andpossessed direct connections to prosperous colonial merchants.Their products, primarily silver plates and bowls, reflected theirexalted status and testified to their customers’ prominence. Silver stood as one of the surest waysto store wealth at a time before neighborhood banks existed. Unlike the silver coins from whichthey were made, silver articles were readily identifiable. Often formed to individual specifications,they always carried the silversmith’s distinctive markings and consequently could be traced andretrieved. Customers generally secure the silver for the silver object they ordered. They savedcoins, took them to smiths, and discussed the type of pieces they desired. Silversmiths compliedwith these requests by melting the money in a small furnace, adding a bit of copper to form astronger alloy, and casting the alloy in rectangular blocks. They hammered these ingots to theappropriate thickness by hand, shaped them and pressed designs into them for adornment.Engraving was also done by hand. In addition to plates and bowls, some customers sought moreintricate products, such as silver teapots. These were made by shaping or casting parts separatelyand then soldering them together. Colonial coppersmith also come of age in the early eighteenthcentury and prospered in northern cities. Copper’s ability to conduct heat efficiently and to resistcorrosion contributed to its attractiveness. But because it was expensive in colonial America,coppersmiths were never very numerous. Virtually all copper worked by Smiths was imported assheets or obtained by recycling old copper goods. Copper was used for practical items, but it wasnot admired for its beauty. Coppersmiths employed it to fashion pots and kettles for the home.They shaped it in much the same manner as silver or melted it in a foundry with lead or tin. Theyalso mixed it with zinc to make brass for maritime and scientific instruments.

单选题 According to the passage, which of the following eighteenth century developments had strongimpact on silversmiths

单选题 In colonial America, where did silversmiths usually obtain the material to make silver articles

单选题 The passage mentions all of the following as uses for copper in Colonial America EXCEPT______.

单选题 According to the passage, silversmiths and coppersmiths in colonial America were similar inwhich of the following ways