Questions about example sentences with, and the definition and usage of "Biggest"

A: × I experienced the most biggest earthquake in my life when I was one year old.
✓ I experienced the biggest earthquake of my life when I was one year old.

× Needless to say I don’t remember because I just turned one year old back then.
✓ Needless to say, I don’t remember it, because I was so young.

Whenever you have an adjective ending with "st" (e.g. highest, funniest, happiest, BIGGEST), there's no need to have a determiner (e.g. most, least) before it, because the "st" already means that it's the most.
Basically, in your sentence, you're saying "I experienced the most most big earthquake in my life." :)

Adding commas (,) when needed, will help your sentence flow better both when reading and speaking.

Also, because you already mentioned that you were one year old in the first sentence, there's no need to mention it again in the second (it sounds unnatural).

Great job though, I hope your English studies continue to go well! :)

A: Google, Amazon, McDonald's, coca cola, など

A: This is one of the biggest drivers of buyer in action.

A: The biggest carnivorous dinosaur now is the supinosaurus.
The supinosaurus has a face like a crocodile's.
They eat sharks.

I have interest in/ I am interested in dinosaurs.
So, I bought a dinosaurs’s picture book.

A: This is quite good! Just a few small things to fix:

"The biggest challenge facing the Japanese medical care system is medical malpractice.
It leads to the damage of patients' benefits and can be lethal in some cases.
As a result, the good relationships between medical staff and patients, including their family members, can be broken.
In case of medical mistakes, staff should apologise to their patient without [hiding](Do you mean physically hiding? Do you mean without avoiding the subject and going straight to the point?).
Furthermore ('Also' is fine, but this looks like a formal piece. Furthermore just adds a bit of complexity), there should be improvements within medical system itself in order to prevent further medical errors.