Вместо точек нужно вставить at, on или in: 1. the celebration is sunday. 2. in great britain cristmas is december. 3. the english lessons is tuesday. 4. it`s my sister birthday friday. 5. the test is wednesday. i`ll have a lot work the weekend. 6. the school starts september.
2.in
3.on
4.at
5.on...at
6.on
Не уверена,должно быть правильно=)