Correct the sentences, if there is not mistake, write RIGHT
Примечания к заданию: Исправить предложения, если в них нет ошибок, написать слово "Right". 1 и 2 как образцы.
Если встретили Past Perfect, то меняем на Past Simple (Встретится 2 раза!)
Во всех остальных предложениях нужно будет поменять Past Simple на Past Perfect, может быть только 1 глагол в Past Simple, который нужно будет изменить, нужно будет найти его, как я понял это когда действие совершено в прошлом, но имеет связь с настоящим. На вас вся надежда.

1. I was pleased to see my old college friends at the conference last week as we didnt see each other since we finished our course | as we hadn's seen
2. We had to wait for hours at the airport because the bad weather had delayed all the flight | Right
3. Many Modern medicines were not invented by western scientists but by tribal people who had been used them for generations before the Europeans arrived.
4. We missed our train, so by the time we reached the theatre , the play ended and audience was leaving the theatre.
5. At the end of their meal they found they couldn’t pay the bill because they didn’t bring any money with them.
6. The children were thrilled when they unwrapped the electronic toys, but when they discovered that nobody bought a battery they were very disappointed.
7. When I came out of the cinema I had found that a thief took my car radio.
8. At first the authorities thought the athlete had been taking drugs, but they soon realized they mixed up the results of the tests.
9. When the film star came into the restaurant I didn’t recognize her because I didn’t see any of her films
10. When we reached the city centre we couldn’t find a parking space, so we had decided to go by bus the nest time.

3. Many Modern medicines were not invented by western scientists but by tribal people who had been using them for generations before the Europeans arrived.4. We missed our train, so by the time we reached the theatre, the play had ended and audience was leaving the theatre.5. At the end of their meal they found they couldn’t pay the bill because they hadn`t brought any money with them.6. The children were thrilled when they unwrapped the electronic toys, but when they discovered that nobody had bought a battery they were very disappointed.7. When I came out of the cinema I found that a thief had taken my car radio.8. At first the authorities thought the athlete had been taking drugs, but they soon realized they had mixed up the results of the tests. 9. When the film star came into the restaurant I didn’t recognize her because I hadn`t seen any of her films10. When we reached the city centre we couldn’t find a parking space, so we had decided to go by bus the next time.-Right