Bodies of water surrounded by land on all sides are called lakes if they're large, and ponds if they're small. Lakes and ponds are formed when water collects (it pools!) in a low place in the ground. Where does all that water come from? Bill ponders this and many other freshwater questions in this exciting program. The DVD has extra features: fully indexed "chapters" correlated to national science standards, interactive glossaries and quizzes, bonus footage of never-before-seen segments, interviews and demos, Spanish translation, and on-disk implementation guide. .