新常态对我国经济的积极意义主要表现为()。
A.生产结构中的农业和制造业比重要明显下降
B.收入结构中的企业收入占比明显下降
C.需求结构中的投资率明显下降
D.动力结构中的人力、资源粗放投入明显下降

单项选择题What does the man say about the aging problem? 14题.mp3 A、The aging problem emerges earlier than expected. B、Citizens over 60 age more repidly than anticipated. C、People are anticipated to age earlier more rapidly. D、The aging problem is not so serious as people expected.

多项选择题我们以一个天平的意象，讨论了教师开慕课投入与回报权衡的观念。可能有哪些方面的回报？