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Slideshare
SlideShare is the best way to share presentations, documents and professional videos.
www.slideshare.net - 2011-01-04 详细 -
AOL.com-美国在线
The new AOL.com brings the Web to you. Get access to email from AOL Mail, AIM Mail, Yahoo Mail and Gmail all in one place.
www.aol.com - 2010-01-28 详细 -
ScienceDirect
www.sciencedirect.com - 2019-10-24 详细