VOA慢速英语:老牡蛎壳改善水质 帮助牡蛎种群

attach - v. to fasten or join one thing to another

mature - adj. having or showing the mental and emotional qualities of an adult

filter - v. to pass (something, such as a gas or liquid) through a filter to remove something unwanted

bushel - n. a unit for measuring an amount of fruit and grain that is equal to about 35.2 liters in the U.S. and to about 36.4 liters in the U.K.

bay - n. a large area of water that is part of an ocean or lake and partly surrounded by land

discard - v. to throw (something) away because it is useless or unwanted

pickup - v. collect something that has been left elsewhere.

knock - v. to hit something (such as a door) with the knuckles of your hand or with a hard object (such as a knocker) in order to get people's attention