Even then, the penguins are cautious; they stay in the water only long enough to feed, and they're adept at remaining motionless when they're on thin ice and spot a leopard seal.
Oil slicks are notoriously difficult to spot in natural-color (photo-like) satellite imagery because a thin sheen of oil only slightly darkens the already dark blue background of the ocean.
浮油出名的难以被发现在天然色卫星图像上，因为稀薄光泽的石油仅仅略黑于深蓝色的大海。
3
The bright spot in a drab employment picture is that workers have been stretched so thin during the past couple years that companies are going to have to (gasp!) hire more.