He managed to conceal the fact that he had been in prison and so got a job as a security officer.他设法隐瞒了坐过牢的事实，找到了一份保安的工作。A security officer at the factory, who declined to give his name, said he had seen two men leave the building.一位不愿意透露姓名的工厂保安人员说，他看到过有两名男子离开大楼。