题目内容

Fossil fuels are renewable，that is，they draw on finite resources that will eventually dwindle，becoming too expensive or too environmentally damaging to retrieve.

查看答案

搜索结果不匹配？点我反馈

更多问题

The word energy can have many different applications，such as when one speaks of the amount of energy (stamina) children have.

The refrigeration system in the central plant of a central system is usually in the form of a heater package with an outdoor condensing unit.

For energy transport, the heat capacity of air is about 3 400 times greater than that of water.

An individual air-conditioning system normally employs either a single, self-contained, packaged room air conditioner (installed in a window or through a wall) or separate indoor and outdoor units to serve an individual room.