9) Perfected the aqualung. 10) The aqualung is a cylinder of compressed air, it is worn on the
back and connected to a mouthpiece.
This is a complete sentence. There are a few ways to tell if a sentence is a fragment or if it’s complete. One of the best ways to tell if something is a sentence fragment is to see if it makes sense on its own. It will typically denote a full, complete thought. If it starts with “when”, “where”, “how”, etc. or “and”, “because”, “or”, etc., it’s typically a fragment. These don’t express a complete thought unless the fragment is added to another sentence or the word is taken away.
Since this sentence makes sense on its own and doesn’t start with the phrases I have mentioned, it is a full thought. It’s a complete sentence. It’s also historically accurate.
How is it a sentence fragment? There is a subject, a verb, and a direct object.