重力的作用点:在物体的____ 上.质地均匀外形规则物体的重心,在它的____ 处.如球的重心在____ .重心不一定在物体上.
— If I work hard at my lessons from now on. Can I do well in them?
— Sure. .
——I'm going to the party on foot.
——If you do, you'll be ___________. The party will start soon.
已知函数fx=12x-x13,那么在下列区间中含有函数fx零点的是( )
时针的钟面上正好是3点正,再过____ 分钟分针与时针重合.