What will repeated word or phrase usually indicate in a primary source?

The correct answer to this open question is the following.

Although you did not include any reference or options, we can say that the phrase that could indicate you are working with a primary source is the one that exactly transcribes what the author says. This makes the source as a valid one, using proper citation.

Let's have in mind that a primary source is information recorded by people who lived in the time of the event and wrote a testimony, a letter, took photographs or videos, depending on the epoch. It also could be news or interviews with characters that were part of those events. That is why, you have to quote the source as it delivered the information, using proper citations and giving the right credit to the sources.

a. poison gas was sprayed over battlefields by airplanes to weaken enemy positions before major attacks.