The revision that correctly combines the two sentences is, "There are seven Wonders of the World; one of the most famous is the Great Pyramid."
Both of the sentences were independent clauses when the were separated. In order to combine the sentences and avoid a comma splice, we need to make sure we separate the two sentences with a semi-colon. When we use a semi-colon, we don't need to use transition words.
The inauguration of the president of the United States is a ceremony to mark the commencement of a new four-year term of the president of the United States. The inauguration takes place for each new presidential term, even if the president is continuing in office for a second term.
