I don't mind living in a topflat. Going up and down stairs will be good exercise for me.
住顶楼，我不在乎。上上下下爬楼梯对我会是很好的锻炼。
2
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》
3
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.