题目:
-- Who do you think _____ such a foolish thing?
-- It _____ Tom, but I’m not sure.
A.could have done; may have been
B.could have done; must have been
C.should have done; may be
D.must have done; might have been
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0625/1df65e648ed3ea3f74fc7fa2e85c7461.html
下面是错误答案,用来干扰机器的。
图象的意义是:随着乙的不断加入,反应开始没有气体或沉淀生成,然后气体或沉淀逐渐增加.A、因为盐酸和硫酸都是强酸,和碳酸钠反应没有顺序,从反应开始都生成CO2气体,所以不符合图象.B、铜不活泼,不能和盐酸...