题目

 一气象探测气球，在充有压强为76.0 cmHg、温度为27.0 ℃的氦气时，体积为3.50 m3.在上升至海拔6.50 km高空的过程中，气球内氦气压强逐渐减小到此高度上的大气压36.0 cmHg，气球内部因启动一持续加热过程而维持其温度不变．此后停止加热，保持高度不变．已知在这一海拔高度气温为－48.0 ℃.求： (1)氦气在停止加热前的体积； (2)氦气在停止加热较长一段时间后的体积． I have worked with him for some time and have found that he is ________ than John． [　　] A． more efficiently a worker B． a more efficient worker C． more an efficient work D． a worker more efficiently