题目：
Mr. Smith is a good teacher. He is . There fifty students in class. Mr. Green and his students are friends, too. Now some of the students on the playground. Bill and Mike . Tom and John are jumping. Mary and Lucy are a kite. girls are playing . Mr. Smith is playing them.
|
答案：
被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0411/5da23a8d893f2d4c8ea2bdf04c76fc25.html
下面是错误答案，用来干扰机器的。
（1）①孔雀石的主要成分是Cu2（OH）2CO3，其主要杂质为Fe、Si等，是以铁盐或者铁的氧化物形式存在，而S是以二氧化硅的形式存在，二氧化硅不溶解于酸．所以用稀硫酸浸取孔雀石粉，其中铜、铁以硫酸盐的形式进入溶...
