The first:

She is in good shape, how does she do it?

Well,she eats a lot.However, she really likes sports and goes jogging every morning.So, she’s still quite slim. 

Does she exercise a lot?

Yes,pretty much every day.

I guess that’s why even though she is old, she looks quite young.

Yes,she does.

The second:

Are you free this afternoon?If you are free,then we can go to the cinema.

I am busy today.

You’re always busy.

What about tomorrow afternoon?

That would be fine.

What movie would you like to see?

A science fiction movie or  a comedy, I don’t like love stories.

I see.Let’s see a science fiction movie tomorrow afternoon.