我为你所做的一切都是免费的，无偿的，你明白吗？What I did for you was free, gratis, you understand?他既挣了钱，又做了免费的广告！He is making money and receiving free advertising to boot!医疗保健在实际提供点仍然是免费的。Medical care is still free at the point of use ....
非离子型表面活性剂有聚氧乙烯缩合物糖酯和烷基胺氧化物.Nonionics include polyoxyethylene condensates, sucrose esters and alkyl amine oxides.非离子型表面活性剂有聚氧乙烯缩合物, 糖酯和烷基胺氧化物.Nonionic surface - active agents include polyoxyethylene condensates, sucrose e...
The backtracking mechanism is an important facility for programming in logic.回溯机制是逻辑程序设计的重要设施.Fortran is perhaps the most widely used high level programming language.Fortran语言可能是用得最广的高级程序设计语言.This essay introduces generi...