But Mr Van Rompuy faces several conundrums.

但是范龙佩面临几个难题。

Marine conservation: the conundrums of the deep dark sea.

海洋保护：黑暗深海中的难题。

The theory, if valid, would address important conundrums facing particle physicists.

这个理论如能被证实，或许就能解决粒子物理学家面临的重要难题。

Like physicists, philosophers play with such conundrums by engaging in thought experiments.

跟物理学家一样，哲学家对于这种难懂的问题采用的是方式是进行思维试验。

More innovative approaches are required to tackle social conundrums and to clear paths for progress.

需要更具创新性的手段从而应对社会难题和为进步扫清道路。