Goldfish are very easy _______. A. for taking care B. to take care C. with taking care of D. to take care of 答案:D现有100 gCuSO4和ZnSO4的混合溶液,向其中加入5.6 g铁粉,恰好完全反应后,过滤,则溶液的质量变化情况以及滤液中的金属离子判断正确的是A.质量变大,Zn2+、Fe2+B.质量变大,Cu2+、Zn2+C.质量变小,Zn2+、Fe2+D.质量变小,Cu2+、Fe2+