课程咨询
托福培训

扫码免费领资料

内含托福全科备考资料

更有免费水平测试及备考规划

托福培训

扫码关注掌握一手留学资讯

回复XDF免费水平测试

托福听力学科背景知识: ALLOY

2018-08-08 11:15:59来源:网络

  为了辅助大家更好地备考托福听力考试,新东方在线托福网为大家整理了一些考试中常见的学科背景知识,了解这些内容,辅助大家更好地了解学科知识,对大家的考试有一定的帮助。下面就让我们来看看本期的学科知识吧!

【点击查看托福听力学科背景知识汇总】

  ALLOY

  Alloys are used more extensively than pure metals because they can be engineered to have specific properties. For example, they may be poorer conductors of heat and electricity, harder, or more resistant to corrosion. Alloys of iron and carbon include cast iron and steels; brass and bronze are important alloys of copper; amalgams are alloys that contain mercury; and chromium is an important additive in stainless steel. Because pure gold and silver are soft, they are often alloyed with one another or with other metals. New alloys are being engineered for use in new technology, including materials for the space program. Metallic glasses and crystalline alloys have also been developed, and metal alloys are sometimes bonded with ceramics, graphites, and organic materials as composites.

  以上就是为大家整理的“托福听力学科背景知识: ALLOY”,更多精彩内容请关注新东方在线托福频道!


托福辅导

关注新东方在线托福

托福机经·Official题目练习

考前重点突破·听说读写海量资料

更多资料
更多>>
更多内容

免费获取托福备考大礼包

微信扫描下方二维码 立即领取

托福辅导
更多>>
更多公益讲座>>
更多>>
更多资料