题目

In ______ 1940s, in ________twenties, my grandfather had to move to the northeast of China to make _________ living. A . the; the; a B . the; his; the C . the; his; a D . a; his; the 答案：C下列做法中不正确的是（　　） A、向污水中加入适量明矾，可除去其中的悬浮物B、用氢氟酸刻蚀工艺玻璃上的纹饰C、从碘水中提取单质碘时，可用无水乙醇代替CCl4D、在海轮外壳上嵌入锌块，可减缓船体的腐蚀速率