Final answer:
The head is most likely to strike the ground first when a small child falls from a significant height, due to their proportionally larger head size compared to their body.
Step-by-step explanation:
When a small child falls from a significant height, the head MOST often strikes the ground first. This occurs due to the proportionally larger head size relative to their body, which can cause them to lead with their head during a fall. It's important for children to be supervised and for adults to take measures to prevent falls from significant heights, as head injuries can be particularly dangerous.