Trade was the mainstay of the urban economy in the Middle East, as caravans negotiated the surrounding desert, restricted only by access to water and by mountain ranges.
因为商队只能通过水路和山脉进入沙漠，贸易就成为了中东城市的主要经济支柱。
2
Poisons from the mines are also killing the village's economy, which depends on clean water to irrigate its crops, says Mr He.
老何说因为村庄需要干净的水来灌溉农田，所以从矿场那过来污染物也让村里的经济受到破坏。
3
It is very efficient and offers great fuel economy, and its only byproduct is water, so it's also a 'green' aircraft.