I swept rainwater off the flattop of a gravestone.
我拂去一块墓碑平顶上的雨水。
《柯林斯英汉双解大词典》
2
If the glass were kept hot enough, it would flow over the molten tin until the top surface was also flat, horizontal and perfectly parallel to the bottom surface.
如果玻璃保持足够的温度，它就会在熔化的锡中流动，直到顶部表面也变得平整、水平，与底部表面完全平行。
3
He hated his red hair so much that he always had on a Yankees baseball hat to cover the flattop he sported.