7200吨=35千克.
故答案为:35.
John always goes to school on foot. But he _____ to school by bus yesterday, because he got up late. [ ]
A. went
B. goes
C. go
肺水肿患者给予高流量氧吸入主要目的是提高肺泡内_______,增加氧的弥散,改善_______。