Resolved questions
What the difference between "too" and "as well"?And between "humanity" and "mankind"?

"Too" and "as well" are pretty much interchangeable. They both can mean "also", but "as well" is more formal. People use "too" when they are speaking casually. There are only a few instances where they are not interchangeable, like when someone says "me too". You don't say "me as well".
Example:
"Taylor, I'm bored."
"Me too."
This is correct.
"Taylor, I'm bored."
"Me as well."
That is not correct.
"Taylor, I'm bored."
"I'm bored as well."
That is correct.
As for humanity and mankind, my understanding is that they are interchangeable, but humanity has other meanings as well.