Relier Pairs NATURAL WORLD (AUDIO)Version en ligne U2. Our beautiful planet. English - 5º PRIM. par Nazaret MR 1 It's smaller than a mountain. 2 It's the natural world (land, water, air, plants and animals). 3 It's smaller than a river. 4 It's a small forest. 5 It's the light and heat produced by burning. 6 It's bigger than a sea. 7 It's a large hole inside rock. 8 It's an area of ground. 9 It's smaller than a rock. 10 It's a large area of land with little water.