Although the coral looks hard, it is very delicate.

虽然那珊瑚看起来坚硬，它其实非常易碎。

《柯林斯英汉双解大词典》

Most Roman pottery is light and smooth to touch and very tough, although, like all pottery, it shatters if dropped on a hard surface.

大多数罗马陶器轻巧而光滑，摸起来很硬，但像所有的陶器一样，如果掉在坚硬的物质上就会碎裂。

youdao

So although I am extremely busy and am working very hard, the pressures are not the same.

所以尽管现在我非常忙碌工作也十分努力，但是压力不可同日而语。

youdao

Although American officials these days do not seem to press the Saudis very hard to become democratic or to uphold human rights, America's media and its rights lobbies are relentlessly critical.

ECONOMIST: The Saudis are hedging their bets

It becomes very hard to reverse this process and lock the metals up again, although it can be done.

FORBES: Fracking With Bad Water

Although the new post- Sarbanes-Oxley accounting regulator, the PCAOB, has been working very hard to update and strengthen many of these standards for the benefit of investors, they have, in reality, had a hard time making substantial changes to many of them.

FORBES: Judge Kaplan: Ernst & Young Must Defend Lehman Investor Lawsuit