分析句子结构We give an analysis of how the hashtag topics changed during the investigated time span and conclude that there are three periods separated by February 12 and March 12.

这是一个复合句，由两个并列的句子构成。

第一个句子结构如下：
主语：We (我们)
谓语：give (提供)
宾语：an analysis (分析)
介词短语：of how the hashtag topics changed during the investigated time span (关于话题标签在调查时间段内如何变化)

第二个句子结构如下：
主语：We (我们)
谓语：conclude (得出结论)
宾语从句：that there are three periods separated by February 12 and March 12 (即有3个时期，分别由2月12日和3月12日分隔开来)

两个句子由并列连词"and"连接。

相关问题

分析句子成分We give an analysis of how the hashtag topics changed during the investigated time span and conclude that there are three periods separated by February 12 and March 12.

主语：We (我们)
谓语：give (提供)
宾语：an analysis (分析)
介词短语：of how the hashtag topics changed during the investigated time span (关于话题标签在调查时间段内如何变化)
并列连词：and (并且)
谓语：conclude (得出结论)
宾语从句：that there are three periods separated by February 12 and March 12 (即有3个时期，分别由2月12日和3月12日分隔开来)

分析下从句We study the real-time Hot Search List (HSL), which provides the ranking of the most popular 50 hashtags based on the amount of Sina Weibo searches.

这是一个复合句，主句是"We study the real-time Hot Search List (HSL)", 从句是"which provides the ranking of the most popular 50 hashtags based on the amount of Sina Weibo searches." 从句是由关系代词"which"引导的定语从句，修饰主句中的"HSL"。从句中介绍了HSL的作用和内容，即提供了基于新浪微博搜索量的最流行的50个hashtag的排名。