We have got wet patches on the wall.

墙上有湿斑。

It had a big wet patch on it. There were fine tendrils of yellow pus on it as well.

上面有一大块湿渍，还有星星点点的脓液。

No amount of positivity, work, or preparation will reduce the chance of say, being kept awake by noisy neighbours the night before an exam or slipping on a wet patch as you run during a race.

再多的积极性、再多的努力、再多的准备也不会减少考试前一晚被吵闹的邻居吵醒的几率，或者在比赛中滑倒在湿地上的几率。