题目

 Having a brother or sister protects adolescents against negative feelings such as loneliness  and guilt, but they also have to learn  to ________ and to control their emotions. A. compete  B. compensate  C. comprehend  D. compromise 答案：D日常生活污水中主要含有碎菜叶、碎塑料薄膜、泥沙、氯化钠和碳酸钠等物质．将这种生活污水处理后可用于冲洗厕所．（1）采取何种操作可除去生活污水中的固体物质______；（2）怎样证明经（1）处理后的水中含有氯离子Cl-______；（3）将生活污水进行处理再利用的主要目的是______．