6个数字复式三中三有多少组

简介：The sound of knocking on the door suddenly stopped, and there was silence for half a minute. Then there was another sound of knocking on the door. No matter how hard I pushed, the back door could not be opened. The reason was that Liu Lei was sitting on Zhang Jiabin's seat, leaning back on his chair to block the back door, and knocked on the door. There was a thunderclap, and Liu Lei shouted: Who is knocking on the door?