Complete using must, have to, need or need to in the correct form and the correct form of the words in brackets

Complete using must, have to, need or need to in the correct form and the correct form of the words in brackets.
1. You ............................................................................ (pay) me back now, but of course you can if you like
2. Dogs ............................................................................... (keep) on a leash at all times.
3. If Linda .......................................................................(pick up) from school tomorrow, maybe we could spend the afternoon in town.

4. We .........................................................................(rely) on phone lines in the future as we'll all have mobile phones which connect to the Internet.
5. The invitations ............................................................................... (send off) soon otherwise they won't get there in time.
 

6. Sorry I'm late. I ........................................ (get) a few things from the supermarket on my way here.