What kind of fruit is this

I try things out grown on trees and stuff, an experts say try it in small amounts. But I'm curious as to what these fruits are growing . I think one them are the Cherry Apples but what is this other one, I seen it before when they fully ripped and bigger they're still green.

The two top ones are either apples or a close relative. The bottom pictures show black walnuts.

yep. i agree on both counts