n.平坦；平滑；平淡

The flatness of the roads made the rest of their trip more comfortable. 道路的平坦使他們剩下的路程舒服多了。

Then, the effect of the working pressure on the flatness of the wafer surface is investigated. 接著，探討加工壓力的大小對于晶圓表面平坦度的影響。

This distressing feeling is caused by the flatness of life and the lack of passion.However, it cannot be simply explained by human nature of insatiability. 對人類這這種因生命的平淡和缺少激情而苦惱和心態(tài)，有時是不能用不知足來解釋的。