掌握物质的分类是学好化学的基础,指出下列物质中属于碱的是[ ]
A.NaCl
B.KOH
C.MgO
D.Cu
答案:B
《中国的科学与文明》一书中写道:“现代研究显示,中国早期官僚政治组织对于科学有发展的强大推动力。”下列各项,不符合上述看法的是 [ ]
A.蔡伦改进造纸术
B.张衡发明地动仪
C.僧一行实测子午线长度
D.宋应星写成《天工开物》
Kate didn't come yesterday, or you ________ her. [ ]
A. might have seen
B. were to see
C. had seen
D. would see