6. The system of claim 5 , wherein the first subject and the plurality of subjects correspond to topicality groups, and wherein the one or more hardware processors is further configured to read instructions from the non-transitory memory to cause the system to perform operations comprising: grouping the a first sub-tree and the plurality of sub-trees by the topicality groups.
6. The system of claim 5 , wherein the first subject and the plurality of subjects correspond to topicality groups, and wherein the one or more hardware processors is further configured to read instructions from the non-transitory memory to cause the system to perform operations comprising: grouping the a first sub-tree and the plurality of sub-trees by the topicality groups. 8. The system of claim 6 , wherein the one or more hardware processors is further configured to read instructions from the non-transitory memory to cause the system to perform operations comprising: displaying an advertisement corresponding to the user needs expression, wherein the advertisement includes an advertising sentiment.