VOA慢速英语:木头能比钢铁更坚硬吗?

component – n. a piece or part of something

polymer – n. a chemical substance that is made of small molecules that are ordered in a simple repeating structure

wind turbine – n. a large machine that is used to produce electricity

dense – adj. having parts that are close together; thick

fiber – n. a thin piece of natural or man-made material

raw – adj. not cooked or prepared; uNPRocessed

cheap – adj. low-cost; not pricey

expensive – adj. costly

binder – n. a cover for holding pieces of paper together