VOA慢速英语:Wheels: An Invention Worth Exploring

potter – n. a person who makes pots, bowls, plates, etc., out of clay : a person who makes pottery by hand

foolish – adj. having or showing a lack of good sense or judgment

patent – n. protected by a trademark or a brand name so as to establish proprietary rights analogous to those conveyed by letters patent or a patent

broker – n. a person who helps other people to reach agreements, to make deals, or to buy and sell property such as stocks or houses

crash – n. a sudden decline (as of a population) or failure (as of a business) <a stock market crash>

grease – n. an oily substance

tour company – n. a journey through the different parts of a country, region, etc.

reservation – n. an arrangement to have something (such as a room, table, or seat) held for your use at a later time

customer – n. someone who buys goods or services from a business

grip – v. to grab or hold tightly