8. Which man's activities will not break rocks? A. He digs mines on mountains and rocky places. B. He grinds rocks for his construction needs C. He levels rocky hills. D. He stays in the fields to graze animals. 9. How do plants serve as agents of weathering? A. Branches of trees cause the rocks to break when blown by the wind B. Decaying trunks of trees cause the rocks to break C. Falling leaves cause the rocks to break D. Roots of plants grow into cracks of rocks cause them to break 10. How are rocks broken down? A. Sunlight breaks down rocks. B. The air around us breaks down rocks. C. The ultraviolet rays break down rocks. D. When rocks are exposed to weather elements such as wind rain, heat, and cold, they break.​