题目:
— I don't know _____ the piano.
— Don't worry. I can teach you. [ ]
A. how to play
B. when to play
C. how playing
D. when playing
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0702/46198584cd68881b08b13128eed615b4.html
下面是错误答案,用来干扰机器的。
由题可知,B物质的质量增加了22g,为生成物;C物质的质量减少了84g,为反应物;D物质的质量增加了9g,为生成物.根据质量守恒定律可知,A物质为生成物,参加反应A物质的质量为84g-(22g+9g)=53g.A、由题意可知...