How to join Activity completion data

Summary:

Hi,

While I was trying to get Completion Date and Completion Status from Activities,

Found that the actual values are from WLF_ASSIGNMENT_TASKS_F table, COMPLETION_DATE and TASK_SUB_STATUS.

Now, my question is, how does WLF_ASSIGNMENT_TASKS_F joins with WLF_LI_ACTIVITIES_F table?

Do I need to join WLF_ASSIGNMENT_RECORDS_F?