The model is based on the interactions of a hypotheticalpopulation of buyers and sellers.
本模式基于买卖双方之间的相互作用之上。
2
The American population is put into context with a hypotheticalpopulation of 1, 000. For example, if America was a population of 1, 000 people, 125 of them would make less than $10, 000.
也就是说如果美国民众数量是1000，他们中的125个将会赚的少于10000美元。
3
This paper deduces a theoretical population model in a urban system under a hypothetical condition of zero population growth (ZPG), and analyses the population dynamics for the model.