...lphabet），按年表排序（Sorting byChronology），按相关性（Ranking by Revelance），根据受欢迎程度（Ranking by Popularity），根据用户和专家的评价（Ranking byusers’ or experts’ratings）,付费排名（Ranking by Pay-for-Placement）。
But a reportbythe BMJwarns that thepopularityofthisrankingis distortingthe fundamentalcharacterofjournals, forcing them to focusmore and more on citationsandlesson readers.
That's down nearly 8% from Facebook's previous ranking, indicating a drop in popularity of the social network that is by far the world's most populous, with more than 900 million active users.