Complete the sentences with 'used to' or 'didn't use to'.

1. I used to play the guitar, but I do now. 2. We used to ride a bike, but we don't anymore. 3. You used to collect stamps, but you don't anymore. 4. I didn't use to enjoy getting up early, but I do now. 5. Maria didn't use to be worried about the environment, but she is now. 6. I used to be afraid of flying, but I'm not anymore. 7. Juan didn't use to know how to use a computer, but he does now.