Though he started late, Mr.Guo played the piano as well as, if________， Miss Liu.
Sometimes we might even need to spend some time making a request.
学校长方形的操场长160米，宽40米，沿操场边沿跑两圈是（ ）米。
下图是地球公转的轨道图，图中甲、乙、丙、丁四点将轨道均分成四等份，读图回答问题。
