Answer:
1.) The article was interesting, but it did not have the information that I needed.
2.) Cats vary in size and many have wild colorings.
3.) We had been traveling for ten hours, and we were happy to reach the motel.
4.) Every morning he makes oatmeal for breakfast, and also fresh juice.
5.) The dog can go to the park and he can go on a hike.
Explanation:
A compound sentence is made up of two independent clauses joined by a coordinating conjunction (for, and, nor, but, or, yet, or so) and a comma or by a semicolon alone.