坐在温馨的物理考场,仔细想想:你平时走路的步幅约为50____,上体育课时你跑100m所需时间约为16____(填上合适的物理量单位).
--- Where's your cousin?
--- He his homework in his bedroom.
抗美援朝战争中用自己的血肉之躯堵住敌人枪口的英雄人物是( )