getline（cin，××）详见http://baike.baidu.com/link?url=U7Fh0grFeQVSqf8bEMv7XpG8UQWnVKgR_Sg85IG12ROGvg_NHTBH1hep6essyWawyDpXXclXkfAnWLPPAcWRq3LvdlVqJEC1kwXKNv_a_w7
getline（）;
