指数可以用于反映一组变量的综合变化.A single index may reflect a composite, or group, of changing variables.在热力学中,我们经常涉及两个或更多变量的函数.In thermodynamics we usually deal with functions of two or more variables.外生变量可以包括内生变量的后滞值.Exogenous variab...
她用火钳再夹一些煤放进炉子里.She used tongs to put some more coal on the fire.她用一把火钳往炉火上再加了一些煤.She used a pair of tongs to put some more coal on the fire.用这个火钳夹煤一点也不困难,顺手得很.It's very convenient to use this pair of fire - tongs to...