Staged combustion avoids the usual wasteoffuel or oxygen used to drive the pumps in an engine with the conventional gas-generator cycle.
分级燃烧，避免了浪费燃料或氧气通常用于驱动发动机与传统的燃气发生器循环水泵。
2
Matthew Yglesias has this right: there were already faster fighter planes in the late ’60s, and by the early ’70s you had the Concorde, but it turned out to be a huge wasteoffuel.
Matthew Yglesias的说法是对的： 在六十年代末，更快的战斗机已经出现。 到了七十年代初期还有了协和式客机，但它最终不过是浪费了大量燃料而已。
3
The increasing use of dried animal waste as a substitute fuel has also hurt the soil because this valuable soil conditioner and source of plant nutrients is no longer being returned to the land.