不知道大家有没有注意过一个奇怪的现象：报纸若是竖着撕，就能直直地撕开；若是横着撕，总是撕偏了、撕个扇形下来。这究竟是为什么呢？看了下面这篇短文，你就知道了。

Newspaper is made up of tiny wood fibers. If you take a close look with a magnifying glass, you'll see that the fibers all line up in the same direction, up and down on the page. This gives the sheet of newspaper agrain.

When you tear the newspaper from top to bottom it tears evenly because you are tearing in the direction of the grain. But when you tear it from side to side, it tears unevenly because you're tearing against the grain.

grain: 纹理（木头的纤维组织的排列、方向或图案）

（英语点津 Annabel 编辑）