class –n. a group of people in a society who are at the same economic and social level

bid –v. to make an offer to pay a certain amount or to do work for a certain amount of money

intellectual property –n. something such as an idea, invention or process that comes from a person's mind

momentum –n. the force that something has when it is moving
 2/3   首页 上一页 1 2 3 下一页 尾页