Which one of the sentences is a run-on sentence? Changes in the economy determine changes in the jobs available, many people will change jobs often during working lives. The proportion of service workers to other types of workers has changed considerably. Manufacturing industries continue to adjust to the evolving global economy. Technological developments have a major impact on the skills needed in the economy. None of these are run-on sentences.

A run-on sentence is when a single sentence contains two or more independent clauses without being joined by proper punctuation or a conjunction. This means that a run-on sentence contains two or more complete sentences fused into one.

Among the given sentences, there are no fused or run-on sentences.

The first sentence contains two independent clauses joined together as a single sentence but it uses a comma to separate the two.

The rest of the sentences contain only a single independent clause, thus making them invalid for a run-on sentence.

Thus, the correct answer is there are no run-on sentences in the given options.