Mr Obama's new rules will bring together a jumble of efforts by various authorities to regulate vehicle emissions and fuel efficiency. 针对奥巴马先生的新办法，太多的当局管理车辆排放和燃料效率时有可能带来一系列的混乱局面。
A multistage operation improves the thermal efficiency. 多层操作可以提高热效率。
Technical measures for increasing heat efficiency of heaters were introduced. 介绍为提高加热炉热效率所采取的技术措施。
