@KhyberBabak The second sentence is just saying that research was done. If there was a third sentence that talked about the results of the research, it can be an argument. We can make an inference on our own that if research on something was done on various eras, it must have existed across civilizations over time, but for an argument, there has to be direct support for conclusion.

If there was a third sentence that said

To research something across different eras, it must have existed across those eras.

Then yes, it is an argument. But we cannot put that in there ourselves even if we can infer it.