Answer:
Millions of Chinese sweep tombs to mourn the deceased and worship their ancestors and the martyrs.
Explanation:
Sweeping tombs is the most important activity during the Qingming festival. People commemorate and show respect to their ancestors by visiting their graves, offering food, tea or wine, burning incense, burning or offering joss paper (representing money), etc. They sweep the tombs, remove weeds, and add fresh soil to the graves.
