glosarium: halaman, 138-140 ; Each page focuses on at least one life cycle. Meet dolphins jumping in the ocean waves, penguins travelling on the ice, and butterflies fluttering in the sky. You'll take a closer look at the life cycles of environments, too. Discover how a river forms and changes over time. Find out how a tree grows and all of the other life cycles it supports within it. See the amazing sculptures the oceans make out of cliffs. Dive beneath the surface to see how coral reefs form, and what causes them to die. Follow the life cycles of weather - from water cycles to ice ages, to give you a better grasp of the climate situation we find ourselves in now.