1) I haven't played tennis since 1990
2)the classrooms are cleaned by Lan and Hoa everyday
3)We collect garbage in the school yard
4)the citizens allowed to use illegal drugs by the government
5)the green house is bigger than the blue house
6)America was discovered by columbus in the 15th century
7)the new building has been designed by mr thinh since 1989
8)I haven't seen him for 2 months
9)i last saw her when she left for Ha Noi
10)lunar new year is celebrated by vietnamese around January or February
11) your taste in art isn't the same as my taste
12) I was at the theater last night and so was he