A. They can portray imagery via the written word by making it stand out with either an underline or in bold letters. B. He uses imagery all the time and an example would be (depending on the story) when Jack and Jill went up the hill to fetch a pail of water and you're able to imagine what it may look like. C. On this one I don't know how to help you. I hope A and B help.
a marriage custom in which a widower marries a sister of his deceased wife. ... a custom among the Yurok of northwestern
The figure of speech used in the lines from sonnet 10 might be personification, in this case, of the word Death. It might be said that personification is the figure of speech in which something nonhuman is given human characteristics. So the "Death" is firstly, personified by introducing it in capital letters, which means it is used as a name, a proper name. then it is given human characteristics, like "proud" "mighty" and "dreadful"
He is using appealing words to help sell of the donkey. This is made clear at the end when it says," Who will bid for this exceptional creature"