VOA慢速英语:大批蝗虫入侵肯尼亚和索马里

swarm – n. a large group of things, usually insects, moving together

outbreak – n. a sudden or violent increase in activity; a rise in disease infection rates

pesticide – n. a chemical used to kill insects

migrate – v. to move from place to place

deterioration – n. the process of becoming progressively worse

instability – n. a lack of security