Other than humans and animals, do you think other things in nature can think? Earth, planets, stars, comet, wind, fire, rocks, plants, etc.

No.

I believe plants and fungi communicate with each other through miccorhizal networks. Here is a fascinating (but lengthy) article, if you are interested.

https://www.smithsonianmag.com/science-nature/the-whispering-trees-180968084/

(Sounds like someone messed up their meds dosage.  Be that as it may…)

Not in the way we'd consider "thinking".  Plants can "communicate" to each other, and sometimes to us, but definitely not like we do.  We don't walk through a forest and literally hear one tree say to another, "Hey bro, check out that cute fir over there”.  Of course, when no one’s around who knows what sounds they may make.  However, we can sometimes tell if a plant is thirsty, as it may be wilted (its way of communicating to us that we haven’t watered it since April).  I believe plants can even feel "pain" (again, not like we do).  And, despite what it may seem like sometimes, I don’t think plants actually commit suicide.  (“What’s the use.  I'm stuck in the same old boring place, and when I try to reach out to someone, they just cut me off”).

Now, we consider things like plants to be "alive" because they grow, reproduce, and die.  Whereas things like a rock simply "is".  Smashing a bolder into pieces of gravel is neither growth nor death.  It’s just in a different form (like changing a dollar bill for 4 quarters).  For centuries, people have been keeping gold bars together but they have yet to reproduce.  As for stars, planets and other celestial things, we may never know if they think, for “in space, no one can hear you scream”.

No, not think, however live things react to the environment for survival.  To mind comes the root that seeks and find a way to expand, the flower that opens to the light or lack of,  the size of trees to keep required individual space.  Rocks are changed by the environment, but not because of their own response to it so that is completely different.    That is all I have right now.  

Possibly not "think", but plants can certainly express distress. That lovely smell of fresh cut grass? That's the grass's way of screaming in agony.

I don't believe so, but there is some data out there that talking to your plants make them grow better.  Frankly, the day they catch me talking to my 49 house plants is the same day they make room for me in the old age home. This post was edited by Spunky at July 8, 2022 7:30 AM MDT

The Scarecrow's "If I Only Had a Brain" song came to mind immediately. 

"I'd think of things I never thunk before. And then I'd sit and think some more".