1. What has he just told ? he told... left
2. they have already left. They haven't been there yet
3. what book did you show me
4. when Polly come home ?she hasn't returned yet
5. how long have they been...
6. the train arrived

3.

1. they often visit....
2. departs
3. .... we are going
4. waits
5. Jack is waiting