In transport the equivalent of a smart meter is a vehicle's on-board unit.
在交通运输领域，相当于一块智能电表的是汽车上的一个车载单元。
2
Coal contains less energy per unit of weight than weight than natural gas or oil; it is difficult to transport, and it is associated with a host of environmental issues, among them acid rain.
煤的单位能量含量低于石油和天然气，而且会导致包括酸雨在内的一系列环境问题。
3
Transport refrigeration mechanics are included in this unit group.