spacing
n [U] amount of space left between objects, words, etc in laying or setting sth out (物体、 字词等之间的)间隔, 间距
Be careful with your spacing or you won´t get the heading on one line. 注意间隔, 否则这个标题一行排不下.
Shall I use single or double spacing (ie single or double spaces between the lines) when I type this letter? 我打这封信是用单行行距还是用双行行距?