Используйте Past Simple или Present Perfect.
1 . Yesterday they __________ a party. (have)
2. Last week wee ___________aa composition. (write)
3. I_______ ___________ to Boston yet. ( not be)
4.The pupils _______ ________ the new rule last Monday. (not)
5. Kate and Jess _______ a nice cat recenrly.( buy)
6. Two days ago my friend and I _____ an UFO.(see)