①在方格纸中,将△ABC向下平移5个单位长度得到△A1B1C1,请画出△A1B1C1;
②在方格纸中,将△ABC绕点O旋转180°得到△A2B2C2,请画出△A2B2C2.
如图所示的四种情景中,属于重力势能转化为动能的是()
My parents will have a big party for my sister's ____ (twelve) birthday.