问题
选择题
Paper-making is _____ of ancient China.[ ]
A. one of greatest inventor
B. one of the greatest inventors
C. one of greatest invention
D. one of the greatest inventions
答案
D
搜题请搜索小程序“爱下问搜题”
Paper-making is _____ of ancient China.[ ]
A. one of greatest inventor
B. one of the greatest inventors
C. one of greatest invention
D. one of the greatest inventions
D
作用产生气体C，B在充足的空气中燃烧生成气体D，C和D的水溶液都呈酸性，并都能使溴水褪色，且C和D混合后不久有固体物质E生成．