So, I really was not all that into the fourth story. - When I read something, I want to be caught off guard a bit, but here the main idea just felt way too obvious to actually be interesting. And even though the story is maybe ten years old, it just happens to be weirdly relevant again right now.
* * * S p o i l e r * * *
Two alien computers head to Earth, looking for intelligent life. Even though there are clear signs that the locals (humans) are intelligent, the computers do not count them as intelligent beings since they are based on protoplasm. So, the ship just keeps moving.
The supposed "argument" of "How can something be intelligent if it just strings together the most likely word every time?" is just flipped around here: "How can something be intelligent if it is based on protoplasm?". But honestly, that reversal is just too on the nose and bland for me to really care.
Since the whole story, unless I missed something, pretty much just leans on that one idea, it is well-meaning on the teaching side (and it throws in some Turing test stuff on the side), but it does not really teach you much, unless maybe you have never come across this kind of thing before.