单项选择题 U.S. News is well known for naming a “Person of the Year” while Time publishes annual ratings of American colleges and universities. A、正确 B、错误

单项选择题 网络诈骗现象还没有引起人们的重视 A、正确 B、错误

多项选择题 β-CD的特点有A. 对酸稳定B. 对热相当稳定C. 对碱相当稳定。D. 对机械作用都相当稳定