Answer:
The correct answers are:
marked - considerable
unseared - pure, uncorrupted
Explanation:
The most interesting feature of my history here was my learning to read and write, under somewhat marked (considerable) disadvantages.
Words like these, I observed, always troubled them; and I had no small satisfaction in wringing from the boys, occasionally, that fresh and bitter condemnation of slavery, that springs from nature, unseared (pure, uncorrupted) and unperverted.
In his stories, Frederick Douglas tries to describe the cruelty of slavery and all the problems that the black people could face because of his/her skin color. In order to achieve that, he uses a strong and authentic vocabulary where some words can be replaced with other words that most closely match the denotation of the words.
In our excerpts, the word <em>marked</em> can be replaced with <em>considerable</em>, while the word <em>unseared</em> can be replaced with <em>pure</em> or <em>uncorrupted</em>.