美语听力 English Café 441（在线收听）

 　　Topics: Ask an American – Saving the oldest photograph; law versus rule versus policy; to stem from versus to be derived from; bring it on; infomercial; hawking; exercise fad

　　Words:
　　studio
　　to show (something) off
　　luminous
　　three-dimensional
　　nanoparticle
　　to scatter
　　nanotechnology
　　unwittingly
　　degradation
　　to corrode
　　chemical mechanism
　　to preserve
　　law
　　rule
　　policy
　　to stem from
　　to be derived from
　　bring it on
　　infomercial
　　to hawk
　　exercise fad
  原文地址：http://www.tingroom.com/lesson/Ecafe/274219.html