Is that a complete sentence? If not what needs to change?
Imagination explores!
Yes, that is a complete sentence
Beyond the horizon, the mountains and the rolling hills stretched as far as the eye could see.
The mountains and the hills.
We went to lake Phalen.
Went.
Everyone sings the song together.
I
I like to go to work because I get to see all my favorite people.
Because
My family likes to go out to eat we go to this Mexican restaurant in our neighborhood.
The cat chased the mouse across the yard.
The cat.
The tall, ivy-covered mansion at the end of the street seemed abandoned for years.
Seemed
Ever since we had college bowl, Maggie won't stop talking about why Purple College deserves to win the Breakthrough Trophy.
D,I
I work with lots of other college students, and we all are from different places.
And
Because the text message I sent to my friend had lots of emojis and exclamation points.
This is not a complete sentence. You need to add another independent clause to it or take out the word because.
Over the hills, a faint sound echoed.
A sound.
Everyone gasped and then became silent.
Gasped and became.
I love to play the guitar, and I even started teaching my sister how to play.
I,I
I like to think I'm a good person, yet sometimes I make mistakes that make me think I'm not.
Yet
Objects in the mirror are closer than they appear
This is not a complete sentence. It needs a period at the end.
The intricate design on the ancient artifact puzzled historians.
The design.
The students are not very funny when they make their inappropriate jokes.
Are and make.
My favorite ice cream flavor is Oreo though sometimes if I'm feeling crazy I will get Cotton Candy.
ID
Whenever.
Literature class is often fun but sometimes Kaia doesn't realize how long she has been talking about complete sentences for and then it is boring.
This is not a complete sentence. You need to add a comma after the word fun (you always need a comma before the FANBOYS if there is two independent clauses. You could also rewrite this a two sentences!
The human body, with all its different functions, leaves lots of room for researchers to explore.
The human body.
Whenever teachers attempt to explain the math problem, I always lost my focus.
Attempt and lost.
My favorite thing about working at Breakthrough, other than getting to know all of the fun and amazing students, is probably working with such cool people and spending time with them outside of work.
I
My friends and I hang out a lot when I'm home from college, but during the school year it is hard to find time to call them.
When and but.