VOA慢速英语:The Ups and Downs of Coffee and Caffeine

interrupt – v. to cause (something) to stop happening for a time

caffeine – n. a substance that is found especially in coffee and tea and that makes you feel more awake

across the pond – idiomatic phrase : that means on the other side of the Atlantic Ocean. It is used to refer to the United States or the United Kingdom depending on the speaker's location

disrupt – v. to cause (something) to be unable to continue in the normal way

circadian rhythm – n. daily rhythmic activity cycle, based on 24-hour intervals, that is exhibited by many organisms

promote ­ – v. to help (something) happen, develop, or increase

hormone – n. a natural substance that is produced in the body and that influences the way the body grows or develops

depression – n. a serious medical condition in which a person feels very sad, hopeless, and unimportant and often is unable to live in a normal way

bipolar disorder – n. any of several psychological disorders of mood characterized usually by alternating episodes of depression and mania —called also manic depression, manic-depressive illness