1. a - "used to" - something in the past (often habits) which do not happen now.Originally Posted by Dany
2. a - other word orders are incorrect.
3. b - correct use of present perfect.
4. c - past simple tense for completed activities.
5. a - present perfect continuous tense for something which started in the past (with words like since or ago) and is still continuing.
Student or Learner