In the 1990s and early 2000s, we used to tackle the problems case by case. Now we changed the method into a more systematic way.

“20世纪90年代到21世纪初，我们曾逐一解决问题。而现在我们采用的是更为系统化的方法。

And forthe kids who prefer to go off by themselves or just to work alone, those kids are seen as outliers often or, worse, as problem cases.

对于那些喜欢独处，或者自己一个人工作的孩子来说，这些孩子常常被视为局外人，或者更糟，被视为问题孩子。

The " crux" (crux) is the most important part of a situation or a story, or in this case, a problem – the main thing, the main idea that's important in understanding the problem.

“症结” （crux）是一个情境或一个故事中最重要的部分， 或者在这种情况下，一个问题——主要的东西， 对理解问题很重要的主要思想。

It’s just a kind of sectarian problem case that threatening to plunge the country back into the dark days of 2006 and 2007 when many thousands dead in a vicious spiral of communal carnage.

这只是一种宗派问题案例，有可能使该国重回 2006 年和 2007 年的黑暗日子，当时成千上万的人死于恶性循环的社区屠杀。