Vietnam's New Year is celebrated accrding to the Lunar calendar . It is officially known as Tet Nguyen Dan, or Tet . It begins between January twenty-first and February nineteen . The exact date changes from year to year . Vietnamese people usually make preparations for the holiday several weeks beforehand. They tidy their houses, cook special food, clean and make offerings on the family altars. On the New Year's Eve , people sit up to midnight to see the New Year in, then they put on new clothes and give one another the greetings of the season. Tet lasts ten days. The first three days are the most important. Vietnamese people believe that how people act during those days will influence the whole year. As a result , they make every effort to avoid arguments and smile as much as possible .  True or False  1. Tet is also called Lunar New Year  2. Tet usually  occurs in late January or early February  3. Vietnamese people make preparations for Tet several months beforehand  4. On New Year 's Eve people usually stay awake until midnight  Choose the best answer  5. What is the main idea of this passage ?  A. Vietnamese people  B. Holidays  C. Lunar New Year  D. New Year's Eve  6. What does the word '' They '' in line 4 refer to ?  A. houses  B. food C. clothes D. Vietnames people