题目原文: Burning coal in power plants produces a waste product called coal ash, a material that contains small amounts of potentially harmful chemicals. Environmentalists in the United States are concerned about the damage such harmful chemicals may be doing to the environment and suggest that th...
Official 41 Task 1 上一题 下一题 Reading Burning coal in power plants produces a waste product called coal ash, a material that contains small amounts of potentially harmful chemicals. Environmentalists in the United States are concerned about the damage such harmful chemicals may be doing to ...