- How long do you think she's gonna be out?
- I'm not quite sure. She received quite a shock. Could be for a few minutes. Most probably, a couple of hours.

8 seconds sound clip from the Back to the Future Part II movie soundboard.

You can hear this line at 00:39:30.669 in the Blu-ray version of the movie.

Quote context

[...]

- We're back.

- Let's put her in the swing. Then I'll take you home, and you can come back in your truck and wake her.

- When she awakens here in her own house and it's dark, you should be able to convince her that it was all a dream.

- Wait a minute. We're just gonna leave her here on the porch?

- The disorientation will help convince her that it was all a dream.

- How long do you think she's gonna be out?

- I'm not quite sure. She received quite a shock. Could be for a few minutes. Most probably, a couple of hours.

- You better bring smelling salts back with you.

- You're the doc, Doc.

- All right. Come on. Let's go, Einie.

- Don't worry. She'll be fine.

[...]