16.A Thông tin:  Tet, or Vietnamese New Year, is the most important celebration in Vietnamese culture.

17.A Thông tin: It takes place from the first day of the first month of the Vietnamese calendar (around late January or early February) until at least the third day. 

18.C Thông tin: “Many Vietnamese prepare for Tet by cooking special holiday food and cleaning the house.”

19.D Thông tin: Many customs are practiced during Tet, such as visiting a person’s house on the first day of the new year, ancestor worship, wishing New Year’s greetings, giving lucky  money to children and elderly people, and opening a shop.

20.D Thông tin: “They start forgetting about the troubles of the past year and hope for a better upcoming year.”