1. The... is the sphere of life waves help to determine the structure of the earth3. The average thickness of the earth's crust is about ...kom4. In spite of its high temperature, the innermost part of the earth's core is5.Igneous rocks are formed on the surface of the earth6. ...... is a sedimentary rock formed by the decay of plant and animal remains7. Limestone is to marble what ...... is to slate.8. Fold mountains are formed by ...... processes.9. Blocks of rock pushed up along a rift form ...... mountains and sunken ble.. State whether the following statements are true or false.1. The core lies between the crust and the mantle.2. Basalt is an intrusive igneous rock.3. Petroleum is found in sedimentary rocks.4. An island may be the top of a volcanic cone rising from the sea floor5. The plates of the lithosphere float on the soft layer of the mantle6. The word 'tectonic' comes from a Greek word which means builder1. Choose the correct options. More than one option may be correct.Which of the following is not a component of the physical environment?ir plants​