VOA慢速英语:Drones to Deliver Fast Food to Virginia Tech University

burrito – n. a Mexican food that consists of a flour tortilla that is rolled or folded around a filling

delivery – n. the act of taking something to a person or place

commercial – adj. of or related to the buying and selling of goods and services

drone – n. a small flying machine flown remotely

hover – v. to stay moving in the air without much movement from side to side

efficient – adj. producing desired results without wasting materials, time or energy

frequency – n. how often something happens