The American continent is larger than the European continent. Just add continent at the end. Or you could say "The American continent is larger than the European one." However, there are two American continents: North and South. You should clarify which one you are referring to. Or say, "Both the North and South American continents are larger than the European one."
The ears of "a" French pug...You must have an article before a noun here.
The rest of the sentences are fine. Your writing is clear and concise. Good luck studying!