VOA慢速英语:Lasers Used to Chill, Instead of Heat

refrigerate – v. to keep something cold or keep it fresh

approach – n. a way of dealing with something

reverse – adj. opposite to what is stated or considered normal

refrigerate – v. to keep something cold or keep it fresh

telecommunications – n.  the technology of sending and receiving signals or images over long distances by telephone, television or satellite

defense – n. the things that are done by a country to protect itself from enemies