Ответ:

1. Did you remember inviting Dave to the party?

2. I stopped working at about 6 because I was getting a headache.

3. You'd better leave now or you'll miss the train.

4. Before exercising, you should warm up your muscles.

5. I expect receiving my results today.

6. I tried logging on last night but I keyed in the wrong password. I remember writing it down somewhere but I've forgotten where I wrote it.