The humorous dinosaurs of Dinosaurs Travel and Dinosaurs Divorce (both 1988) are back with some sensible, enthusiastic suggestions for minimizing waste, garbage, and pollution. Readers are urged to do something positive for the environment: conserve, recycle, or think of new uses: people can make a difference simply by turning off the water while brushing their teeth (saving a gallon a minute), or by eating a natural snack like fruit to avoid excess packaging. Children will delight in the busy, cartoon-style illustrations and chuckle over the antics of ``Slobosaurus,'' who is full of excuses for why he can't be bothered with protecting the planet. Printed on recycled paper, these are useful suggestions with great kid appeal. (Nonfiction. 4-8)