What is the main idea of the third and fourth paragraphs?

Explanation:

I could not find the rest of the question but I will try to help you by explaining how can you find the main idea in some paragraphs.

The main idea of some passage or paragraph is considering what the passage\ paragraph is about. You can find it by reading the text couple of times and see what the text is describing and explaining to you.

When you find what the text is about, you will know what is the main idea of it.

technology

Explanation:

in the ancient times they did not have and by now they have grown old and probably dont remember much due to their age and they can't be blamed for that.