分析句子Based on that data, we have been able to track the evolution of public attention in different periods during the pandemic, follow how the attention of the population shifted from one group of topics to another and study the changing correlation patterns of different COVID-related topic categories with the evolving COVID-19 situation in the world.

这个句子是一个复杂句，包含一个主句和两个并列的从句。其中，主句是 "we have been able to track the evolution of public attention in different periods during the pandemic, follow how the attention of the population shifted from one group of topics to another and study the changing correlation patterns of different COVID-related topic categories with the evolving COVID-19 situation in the world"，从句1是 "Based on that data"，从句2是 "with the evolving COVID-19 situation in the world"。主句中描述了基于数据所做的工作，包括追踪公众关注度的演变、关注度的转移以及研究不同 COVID-19 相关话题类别的变化关联模式。从句1中说明主句的内容是基于数据的，从句2中进一步说明主句中研究的对象是全球 COVID-19 疫情的演变情况。整个句子的意思是：基于这些数据，我们能够追踪疫情期间不同阶段公众关注度的演变、关注度的转移，以及研究不同 COVID-19 相关话题类别的变化关联模式，这些工作都是针对全球 COVID-19 疫情的演变情况进行的。

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。