After graduating, he interned at Microsoft.

毕业后，他在微软实习。

He was interned as an enemy alien at the outbreak of the Second World War.

他在第二次世界大战爆发时被作为敌国侨民扣押了。

Now what's a interned string?

现在，什么是实习字符串？

One who is interned; an internee.

拘留犯被拘留者；

The state of being interned; confinement.

拘留被拘留状态；

An alternate option here is to use interned strings.

这里，一种替代选择是使用Interned字符串。