Sound effects?

Okay, look Im trying to make a movie, I import my stopmotion movie think maybe I movie has a punch sound effect, but no. I mean why is there no punch sound effect its the simplest sound ever to add, why is it not add. Apple should have a separate app or something that has a ton of sound effects that you can import to I movie, like wouldnt it be cool to be a able to make a simple movie with every thing you need, its just I dont get why they dont have a sound effect as simple a punch. I hope they can improve there sound effects to make the movie making a little bit easier, thats all.

Popup890 about iMovie, v2.2.3