Final answer:
During the civil wars in China, many people became Buddhists to help the poor and needy, while Tang rulers attempted to destroy Buddhism.
Step-by-step explanation:
The civil war mentioned in the question refers to internal conflicts within China that caused great suffering among its people. During these times of hardship, many individuals stepped forward to assist the poor and needy. The Tang rulers, fearing the influence and power of religion during such unstable times, sought to destroy certain groups that they viewed as threats to their rule.
Given the historical context provided, the correct answer to fill in the blanks would be: Many became Buddhists to help the poor and needy. Tang rulers try to destroy Buddhism. Thus, the completed sentence would read: Many became Buddhists to help the poor and needy. Tang rulers try to destroy Buddhism.