What is the relationship between the central ideas and supporting details in a text

The supporting details provide examples and claims in support of the central claim/ ideas that an author may make in his/ her work.

Explanation:

The central idea of a text is the main idea or point that the author wants to make in his text. This presents the main idea(s) for the understanding of the audience/ readers and makes a unified claim of what the story is about.

The supporting ideas of a text are the ideas or claims/ arguments, examples, or statements that give an explanation or support for what the main claim(s) is. This is like an evidence/ proof of what the author claims in his text.

So, when the supporting ideas are present in any text, they act as the support for any claim that an author may make. Without these supporting details, it can be a bit difficult for readers to understand or even accept the claims made by the author. Thus, the central idea and the supporting details work hand in hand, in that the supporting details act as the "support" or proof of the claims made in the central idea.

the following key ideas correctly express the key sentence.

restate key idea: most people can learn to swim in ten short lessons.

restate key idea: the majority of water-accident victims require mouth-to-mouth breathing.

restate key idea: an empty, tightly closed gallon jug will support a tired swimmer.  

restate key idea: first aid is to prevent accidents as well as assist in rescue.

explanation: the key idea needs to have the same topic as the key sentence (drowning and safety).

yes

explanation: