nǐ / zhēn shì / shǎo gēn jīn / zhè me / jiǎn dān / de / dào lǐ / dōu / xiǎng / bù / míng bái

你真是少根筋，这么简单的道理都想不明白。

You really are a bit dim-witted; you can't even understand such a simple reason.