一次帮一个人骑一辆自行车

foundation – n. an organization that is created and supported with money that people give in order to do something that helps society

courage – n. the ability to do something that you know is difficult or dangerous

mountain bike – n. a type of bicycle that has a strong frame, thick tires, and straight handlebars and that is used for riding over rough ground

donor – n. a person or group that gives something (such as money, food, or clothes) in order to help a person or organization

contest – n. an event in which people try to win by doing something better than others

check – v. to look at (something) carefully to find mistakes, problems, etc., or to make sure there is nothing wrong with it

lockdown – n. a security measure taken during an emergency to prevent people from leaving or entering a building or other location:

routine – n. a regular way of doing things in a particular order

sustainable – adj. able to last or continue for a long time