Astheproverbgoes,manstrugglesupwards;waterflowsdownward...
问题详情:Astheproverbgoes,manstrugglesupwards;waterflowsdownwards.Waterrunsdownhillfrommountaintopstostreams,toriversandtooceans.Butdownhillisn'ttheonlywaythatwatermoves.Anewstudymeasureshowwatertravelsfrom...