You can use discover, find, or find out to talk about learning that something is the case. He discovered the whole school knew about it... The young child finds that noise attracts attention... We found out that she was wrong. Discover is a slightly more formal word than find, and is often used to talk about scientific research or formal investigations. For example, you can discover a cure for a particular disease. You can also use discover when you find something by accident. This well-known flower was discovered in 1903. If you cannot see something you are looking for, you say that you cannot find it. You do not use 'discover' or 'find out' in this way. I'm lost — I can't find the bridge. You can say that someone finds out facts when this is easy to do, but you cannot use 'discover' or 'find' in this way. I found out the train times.

discover, find, find out 都可以用于描述获知事实情况：He discovered the whole school knew about it...（他发现整个学校都知道这件事了），The young child finds that noise attracts attention...（小孩子发现吵闹能吸引注意力），We found out that she was wrong（我们发现她错了）。discover 比 find 稍正式，并常用于谈论科学研究和正式的调查。例如，可以用于表示发现治疗某种疾病的方法，还可以指偶然间的发现：This well-known flower was discovered in 1903（这种著名的花是 1903 年发现的）。找不到某物用 cannot find somthing, dicover和 find out 则无此用法。如：I'm lost — I can't find the bridge（我迷路了，我找不到那座桥了）。find out 可以指弄清很容易就发现的事实，但 discover 和 find 则无此用法：I found out the train times（我查到了列车时刻表）。