实验室用取大理石12.5g，加入盛有100g稀盐酸的烧杯中，两者恰好完全反应（假设其他杂质不与盐酸反应，也不溶解）。烧杯内物质的质量变为108.1g。试计算:

①能制取二氧化碳多少g ?

②大理石中碳酸钙的质量分数？

根据短文，现在请同学们为Mr. Cao填完整他工作日的日程安排表
   Mr. Cao is a teacher in a middle school．He has a lot of things to do from Monday to Friday．On Monday and Tuesday morning he has three speaking classes．On Thursday he has two writing classes in the morning and one in the afternoon．He plays ball games after class on Monday and listens to music on Tuesday afternoon．He doesn’t have classes on Wednesday or Friday．He works on the computer on Wednesday morning．He can speak a little Japanese．So he takes Japanese classes that afternoon．On Friday morning．Mr. Cao meets old friends．In the afternoon，he has a rest at home