Supply the correct tense of the words given in each blanket

Supply the correct tense of the words given in each blanket.

1. Four countries ______________ (visit) by John so far.
2. London ______________ (have) a population of eight million people.
3. The Statue of Liberty in New York is a monument which ______________ (symbolize) freedom.
4. Vietnam’s Independence Day ________________ (celebrate) on September 09th.
5. We ______________ (visit) Sydney Opera House for several times.
6. Some activities ______________ (prepare) to celebrate the lunar new year now.