Thanks Irfee for the essay and thanks to Ramesh789 for the comments - it's a big help.
Irfee, I agree with Ramesh789 that we need the original question. Do you have it? If you can post it here that would help us to see if your essay answered the question or not.
Learn from mistakes....
As we know that we are living in fast world
This is not a sentence. It’s a fragment. The problem is caused by the incorrect phrase ‘As we know that.’ Leave out ‘that’ and add a comma.
As we know, we are living in a fast world.
But if we know it, then there is no need for you to say it. So your first sentence can now be written
As we know that we are living in fast world and we must have good health for facing any challenges of the society.
We are living in a fast-paced world, and need to be healthy to face its challenges.
(You had the same wrong structure ‘as we know that’ in another essay and it was corrected. Make sure you learn from your mistakes!)
You have one beautiful sentence in Paragraph Two
There are several reasons why it is ridiculous to expect free or subsidized health care indefinitely.
It’s very nice, but it’s not really your sentence – it comes from here.
Your topic sentence for Paragraph Three
However, it’s also natural to fight for life
- also comes from the same essay.
There’s not much point in people helping you with your essays if they are not your essays! ( مضمون کی چوری٬ بجری کی تہہ)
Looking forward to some careful posts by you with your own writing and ideas. We can all improve together.