Benjamin Franklin produced some of his best writings at the age of 84, and Pablo Picasso put brush to canvas right through his eighties.
2019年12月六级真题（第一套）听力 Section B
Several years ago when my grandparents were well into their eighties, they were faced with the reality of no longer being able to adequately care for themselves.
When you talk about the eighties, you are referring to numbers between 80 and 89. For example, if you are in your eighties, you are aged between 80 and 89. If the temperature is in the eighties, the temperature is between 80 and 89 degrees.