I'm confused with whether I should use "these" or "those" in the context of writing a paper or report in the specific example below. I don't know how I can do it differently:
1) To detect abnormal features in a patient's organs, a health provider can tap a patient's body parts to cause sound waves. _____(These/ Those) sound waves will be reflected by a patient's organs and heard by a health provider.
2) Unsuccessful interaction can lead to a patient's negative health outcomes. ______(This/ That) is because unsuccessful communication...
3) Herbs can be used to make medicine. Because of (this/that).......
4) Tapping is a good technique for abnormal findings. _____(This/That) technique can also be used to.....
Every time I'm in the situation above. I don't know what to do.
On one hand, I feel that "this" and "that" (or the pair "these" and "those") can be interchangeable in the case of writing a report or a paper as:
"This"/"These" can be used to refer to something mentioned in the previous sentence
"That"/"Those" can be used to refer to something that happens in real life or in the outside world.
On the other hand, I think there should be rules when this,that,these, and those are being used in an essay/ report/ paper.