VOA慢速英语:快速蔓延的海胆在加州和俄勒冈州破坏海洋生态

kelp – n. a large, brown plant that grows in the sea

reef – n. a line of rocks or sand at or near the surface of the sea

barren – adj. unable to produce plants

uncharted – adj. never before described

species – n. a group of plants or animals that share similar qualities

desperate – adj. needing or wanting something very much

drone – n. an unmanned aircraft guided by remote control