a_list = soup.select("a.post-link")
方向遍历顺序说明下一个倒序（从右往左）先处理右侧，栈里存「右侧候选」上一个正序（从左往右）先处理左侧，栈里存「左侧候选」
，详情可参考safew官方版本下载
Mobile operators are rolling out technologies like 5G and 5GSA, says Elliot, which will allow them to connect many, many more customers in and around venues.
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Жители Санкт-Петербурга устроили «крысогон»17:52