知乎，让每一次点击都充满意义 —— 欢迎来到知乎，发现问题背后的世界。 RAND is usually a investigation Firm that develops options to public coverage issues to help you make communities all through the entire world safer and safer, more healthy plus much more prosperous. RAND is nonprofit, nonpartisan, and devoted to the public curiosity. And a number of other authors https://elizabethm294oqr3.onzeblog.com/profile