That alone will challenge old rules of thumb about the relative riskiness of emerging-market debt.

楼主翻成关于新兴务风险的估仅凭这个就会受到质疑。

As a rule of thumb you need a litre of paint to every 12 square metres of wall.

根据经验粗一下，每12平方米墙面需要一升涂料。