VOA慢速英语:海豹离开美国东北部意味着要学会和鲨鱼一起生活

prefer – v. to like one thing better than something else

occasionally – adv. sometimes but not often

uNPRovoked – adj. happening without a reason or apparent cause

unequivocal – adj. without doubt, very clearly the case

cautious – adj. careful about avoiding danger