plains 是 plain 的第三人称单数、复数

plain

KK [plen] /pleɪn/

形容词

1
清楚的、明白的、显而易见的
It was plain to everyone that she had been crying.
大家都看得出来她刚刚哭过。
2
朴素的、简单的、不花俏的
They served plain food, but everything tasted fresh.
他们端出来的是家常菜，但每一样都很新鲜。
3
素色的、无图案的
I prefer a plain shirt to one with stripes.
我比较喜欢素色衬衫，不喜欢有条纹的。
4
直率的、坦白的、不客气的
Let me be plain with you about the risks involved.
关于其中的风险，我就跟你直说了。
5
纯粹的、十足的、完全的强调用法
Ignoring the warning signs was plain stupidity.
无视那些警告标示简直就是愚蠢。
6
不好看的、长相平庸的委婉
She described herself as a plain but confident woman.
她形容自己是个长相普通但很有自信的女人。
7
平坦的
The road ran across the plain, dry countryside.
那条路横越干燥平坦的乡间。

1
平原、平地常用复数
Herds of wild horses still roam these northern plains.
成群的野马仍在这片北方平原上奔驰。

1
简直、完全、根本口语
His answer was just plain wrong, and everyone knew it.
他的答案根本就是错的，大家心里都清楚。