VOA慢速英语:博茨瓦纳将大象死亡归咎于有毒藻类

neurological –adj. related to the nervous system which includes the brain, spinal cord and nerves

toxic –adj. containing a poisonous substance

source –n. the beginning of a river or stream, a place where water can be found

delta –n. a triangular area on a river where it widens and usually flows into the ocean

tourist –n. a person who travels for pleasure

paralysis –n. the inability to move a limb or body