Нужно вставить: Was/ were able to, could (n't), had been able to, should be able to or can/
1. You … run much faster when you were younger. 2. On entering the house I … smell something burning in the kitchen. 3. If you work quickly, you … finish on time. 4. Ann (not) … read yet though she’s almost six. 5. When we lived on the coast, we … swim in the sea every day. 6. Gordon survived because he … find his way out of the jungle. 7. Last week he … arrange a meeting with the Prime Minister. 8. I’m not usually very good at tennis, but yesterday I … beat my brother. 9. Tom (not) … finish his work for three days. Something’s gone wrong. 10. He (not) … fix the tap so he called a plumber. 11. He read the message but he (not) … understand it. 12. Our baby … walk in a few weeks. 13. Although the pilot was badly hurt he … explain what had happened.

1. You were able to run much faster when you were younger.

Explanation: "Were able to" is used to talk about past abilities or skills.

2. On entering the house I could smell something burning in the kitchen.

Explanation: "Could" is used to talk about general ability in the past.

3. If you work quickly, you should be able to finish on time.

Explanation: "Should be able to" is used to talk about future possibilities or expectations.

4. Ann couldn't read yet though she’s almost six.

Explanation: "Couldn't" is used to talk about inability or lack of ability in the past.

5. When we lived on the coast, we could swim in the sea every day.

Explanation: "Could" is used to talk about general ability in the past.

6. Gordon survived because he was able to find his way out of the jungle.

Explanation: "Was able to" is used to talk about past abilities or skills.

7. Last week he was able to arrange a meeting with the Prime Minister.

Explanation: "Was able to" is used to talk about past abilities or skills.

8. I’m not usually very good at tennis, but yesterday I was able to beat my brother.

Explanation: "Was able to" is used to talk about past abilities or skills.

9. Tom hasn't been able to finish his work for three days. Something’s gone wrong.

Explanation: "Hasn't been able to" is used to talk about inability or lack of ability in the past until now.

10. He hasn't been able to fix the tap so he called a plumber.

Explanation: "Hasn't been able to" is used to talk about inability or lack of ability in the past until now.

11. He read the message but he couldn't understand it.

Explanation: "Couldn't" is used to talk about inability or lack of ability in the past.

12. Our baby should be able to walk in a few weeks.

Explanation: "Should be able to" is used to talk about future possibilities or expectations.

13. Although the pilot was badly hurt he could explain what had happened.

Explanation: "Could" is used to talk about general ability in the past.