system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If stomach acid is so strong, how do some foods get through into our stool without being broken down (like seeds?)
gpt
Because acids are strong only with substances they can react to. That's why we kept sulfuric acid in glass and nothing happened.

Now those seeds are made of a material that does not get dissolved or digested very well, so it remains whole through the trip to wave you good-bye.