Fill in the gaps with the right form of the verb: Use: was able, have to, shouldn’t, will be able, couldn’t, could, can’t

Fill in the gaps with the right form of the verb: Use: was able, have to, shouldn’t, will be able, couldn’t, could, can’t 1. When I looked at the test, I couldn't answer many questions. 2. My camera doesn’t work, so I can't take any pictures. 3. If I learn English, I will be able to understand people abroad. 4. The singer had a sore throat. However, she was able to sing at the concert. 5. He could sing very well when he was twenty. 6. You shouldn't eat a lot of sweets. 7. They didn’t have to go to school.