AP是Advanced Placement的缩写，中文一般翻译为美国大学先修课程、美国大学预修课程。指由美国大学理事会（The College Board）提供的在高中授课的大学课程。
economics -the study of choices people make in a world of limits choice- the act of selecting one of many alternative things to do or consume scarcity- people cannot have everything they want ；resources and goods are limited compared to desires.
resources- things that are used to make goods. Sometimes called factors or inputs. These include land, labor, skills, capital, and natural resources.
land- the resource of space, especially when used to produce food. Generally, land can usually be used over and over without vanishing. labor- the time of people as they work to produce things. skills- ability, talents, and training enabling people to produce things.
capital- a man-made resource, such as machines, tools, and equipment. Capital usually lasts a long time, and can be used without being used up.
natural resources- resources such as oil, coal, minerals, lumber, and water which can be extracted from nature or produced in time with its help.