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日本红怡院一本道_七次狼视频1线在线播放_91大杳焦_最新成年轻人网站视频下载

时间: 2019年12月13日 21:16

� Now this was perplexing. The nuchal ligament is useful only for stabilizing the head when ananimal is moving fast; if you鈥檙e a walker, you don鈥檛 need one. Big butts are only necessary forrunning. (See for yourself: clutch your butt and walk around the room sometime. It鈥檒l stay soft andfleshy, and only tighten up when you start to run. Your butt鈥檚 job is to prevent the momentum ofyour upper body from flipping you onto your face.) Likewise, the Achilles tendon serves nopurpose at all in walking, which is why chimps don鈥檛 have one. Neither did Australopithecus, oursemi-simian four-million-year-old ancestor; evidence of an Achilles tendon only began to appeartwo million years later, in Homo erectus. � Chapter 5 A Crisis in My Mental History. One Stage Onward � � 日本红怡院一本道_七次狼视频1线在线播放_91大杳焦_最新成年轻人网站视频下载 � � � � �