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6.which of the following is a run-on sentence?

A.terri had a hard time continuing the tour she was so tired from the day's events.(I PICK A)
B.som students decided to rest,so they returned to their hotel.
C.washington is a great place to visit because there are so many exciting places to

Right.

are you sure??

Yes. I taught secondary English for many years.

http://grammar.ccc.commnet.edu/grammar/runons.htm

To determine which of the following sentences is a run-on sentence, we need to understand what a run-on sentence is. A run-on sentence is a sentence that contains two or more independent clauses without proper punctuation or conjunctions.

Now, let's analyze the sentences:

A. Terri had a hard time continuing the tour; she was so tired from the day's events.
This sentence is not a run-on sentence because it contains proper punctuation (semicolon) to separate the two independent clauses.

B. Some students decided to rest, so they returned to their hotel.
This sentence is not a run-on sentence because it contains proper punctuation (comma) and a coordinating conjunction ("so") to connect the two independent clauses.

C. Washington is a great place to visit because there are so many exciting places to...
This sentence is a run-on sentence because it contains two independent clauses ("Washington is a great place to visit" and "there are so many exciting places to...") without proper punctuation or conjunctions to separate them.

Therefore, the correct answer is C: "Washington is a great place to visit because there are so many exciting places to..."