Hxen.com's tips：Every day persisted can learn English well!-->■Learn English Everyday■
species – n. a particular group of things that belong together or have some shared quality
toxin – n. a poisonous substance and especially one that is produced by a living thing
red tide – n. a discoloration of seawater caused by a bloom of toxic red organisms
algae – n. simple plants that have no leaves or stems and that grow in or near water
