Answer:
1. Peter paid for Emily's ticket (to pay)
2. We were in the park this morning. (to be)
3. Не visited his friend in 2013. (to visit)
4. The bird flew high in the sky. (to fly)
5. She was not in last year. (not to be)
6. We were in the park this morning. (to be)
7 The Olympic Games did not finish last month. (not to finish)
Step-by-step explanation:
The correct form of past to fill the given sentences would be simple past. As we know, the simple past tense is employed to denote the actions which were completed in the past(recent or distant). It is framed using 'subject + IInd form of the verb + object' in affirmative while 'sub. + did + not + V1 + object' for negative sentences. Since the given sentences talk about past actions, they will employ V2(base form of the verb + 'ed'/d).