~のだから (given that / because)

Writing novels takes practice too, just like drawing.

The light's on, so they can't have gone out.

Since she's been studying French for a full ten years now, she should be quite familiar with what French is all about.

You heard the story, so you must be interested.

It's not even the rainy season, so you don't need an umbrella, do you?

She's already quit her job, so we can't rely on her.