Final answer:
The amount of human bone that is living tissue is represented by the decimal 0.70. This indicates that 70% of a bone's makeup is living tissue.Hence, the correct answer is option D.
Step-by-step explanation:
The decimal that represents the amount of a human bone that is living tissue is 0.70. Human bones consist of water, minerals, and living tissue. While the water and minerals make up a portion of the bone structure, the living tissue is a significant part, making up the remaining percentage after water and mineral content is accounted for. Since we are not given exact percentages for water and minerals, we can assume that the rest, being the living tissue, constitutes a major part of the bone's composition.