好东西，虽然不是很难，但是这样可以节省不少时间，可以把精力投入到难度较大的改进以及应用上了，而不用在大家都会的基本程序上花挺多时间-Good things, though not difficult, but it saves a lot of time can focus into the more difficult to improve as well as the application, and not everyone will be in the basic procedures