Water behaves oddly when it freezes. Most substances contract as they cool, b ice occu more sp than t water i came fr, because ea molecule lo into a ri lattice wi gaps inside it. The frozen layer therefore floats instead of sinking to the bottom of the lake. That single accident of chemistry keeps the water underneath liquid all winter, and the fish and insects living in it survive until spring.

Type only the missing letters. Each box is one letter, and the number of boxes matches the letters that are missing.