Final answer:
The run-on sentence is: 'Changes in the economy determine changes in the jobs available, many people will change jobs often during working lives.'
Step-by-step explanation:
A run-on sentence is a sentence where two or more complete sentences are not separated by any punctuation. To determine which of the sentences provided is a run-on sentence, we need to look for sentences that are not properly punctuated. Let's analyze each option:
Changes in the economy determine changes in the jobs available, many people will change jobs often during working lives. This sentence is a run-on sentence because it is trying to combine two complete sentences without any punctuation. To fix this, we could add a coordinating conjunction like 'and' or separate the sentences with a period.
The proportion of service workers to other types of workers has changed considerably. This sentence is correctly punctuated and is not a run-on sentence.
Manufacturing industries continue to adjust to the evolving global economy. This sentence is correctly punctuated and is not a run-on sentence.
Technological developments have a major impact on the skills needed in the economy. This sentence is correctly punctuated and is not a run-on sentence.
None of these are run-on sentences. This is not a sentence, but a statement. It is correctly punctuated and is not a run-on sentence.
Therefore, the run-on sentence is: Changes in the economy determine changes in the jobs available, many people will change jobs often during working lives.