Most structures require one " area " on the planet and one " population " unit for each level , although there are some exceptions ; for example , urban structures do not require a population unit , and terraforming and orbital bases require neither area nor population 每次升級(jí)建筑都要占用一個(gè)空間和一個(gè)人口單位,也有些一例外:比如,城市建筑不需要占用人口單位,地形改造器和軌道基地產(chǎn)都不需要占用空間也不需要占用人口。