You sure a bullet can stop a Martian?
4 seconds sound clip from the X Minus 1 - Mars is Heaven by Ray Bradbury classic radio dramaseries.
You can hear this line at 00:12:22 in the radio play.
Quote context
[...]
- Come on, Horst. Where're going to ring that doorbell.
- There's got to be a scientific answer to all this.
- There's something moving in there.
- Stand back. Give me a clear shot.
- You sure a bullet can stop a Martian?
- If you're selling anything, it's much too early.
- No, no wait just a minute. What town is this?
[...]