Period Sixliftedwere drivingstarted本课栏目开关语法感知知识储备语法感知Period Sixplayedhas won语法感知本课栏目开关语法感知知识储备Period Six知识储备本课栏目开关语法感知知识储备Period Six知识储备本课栏目开关语法感知知识储备Period Six知识储备本课栏目开关语法感知知识储备Period Sixgavedidnt seerealizedmovedwalkedwent知识储备本课栏目开关语法感知知识储备Period Six知识储备本课栏目开关语法感知知识储备Period Six知识储备本课栏目开关语法感知知识储备Period Six知识储备本课栏目开关语法感知知识储备Period Sixwere havingwas singingwere discussingwas travelling知识储备本课栏目开关语法感知知识储备Period Six知识储备本课栏目开关语法感知知识储备Period Six知识储备本课栏目开关语法感知知识储备Period Six知识储备本课栏目开关语法感知知识储备Period Six知识储备本课栏目开关语法感知知识储备Period Sixhave finishedhas livedhas doneis/has been知识储备本课栏目开关语法感知知识储备