When it comes to old-fashioned removal methods, they're troublingly tenacious.

说到老式的清除方法，它们的顽强程度令人不安。

There really is no reason why the expansion can't keep going. Inflation is not troublingly high.

经济扩张不能持续实在没有理由。通货膨胀不太高。

But we do know that central to the existence of these RSLs are perchlorates -- corrosive, toxic ionic compounds that are, troublingly, abundant on Mars.

但我们确实知道，这些 RSL 存在的核心是高氯酸盐——腐蚀性、有毒的离子化合物，令人不安的是，它们在火星上大量存在。

And what I've learned is that though the world loves to remind Africaabout its vast clean-energy potential, the financial flows to deliver that potentialremain troublingly scarce.

我所了解到的是， 尽管世界喜欢提醒非洲其巨大的清洁能源潜力，但提供这种潜力的资金流动仍然非常稀缺。

And I found and what I've learnedis that though the world loves to remind Africaabout its vast clean energy potential, the financial flows to deliver that potentialremain troublingly scarce.

我发现并了解到， 尽管世界喜欢提醒非洲其巨大的清洁能源潜力，但实现这一潜力的资金流动仍然非常匮乏， 令人不安。