Question

Which one is a run-on sentence?
Select the correct answer.
After the winter thaw and the spring rains, the river rose and
flooded the entire valley.
It is necessary to guard the reservoir carefully to keep the water
safe from contamination.
The superintendent realized that her secretary was not only loyal
but also efficient all her work was perfect.
How did we ever accumulate all this junk in the garage?

Answer 1

Answer: I believe it’s the second one

Explanation:

Answer 2

Answer:

C. The superintendent realized that her secretary  was not only loyal but also efficient all her work was perfect.

Explanation:

A run on sentence, is a sentence where two or more independent clauses are not joined correctly. You can see that the two independent clauses here, are

The superintendent realized that her secretary was not only loyal, but efficient.

And

All of her work was perfect.

These two clauses should be seperated by using a comma, or can be two completley different sentences, because they can stand as their own.