In land animals, saliva contains mucus, and provides lubrication for food in the alimentary canal.陆上动物的唾液内有粘液, 并对消化道内的食物起着润滑作用.In metal lubrication two distinct regions are recognized: boundary and hydrodynamic.在金属的润滑作用中...
He went backstage and asked for her autograph...他去后台跟她要了签名。When police realised who he was, they asked for an autograph and let him off with a warning.警察知道他是谁后，便向他要了签名，然后只给了他个警告就放他走了。Does she ever get asked for her autog...