The word which best completes the given sentence is:
This is a type of tense which has to do with the action which is active and occuring and is more active than the present tense because it is continuous.
With this in mind, when living creatures in the Great Barrier Reef are spoken about, we can see that they are in present continuous form as they still live there without being studied.
Read more about present continuous tense here:
https://brainly.com/question/25769275
