Three formal requirements for writing expository prose are:
omission of contractions
use of standard english
avoidance of sentence variety
intentional use of technical jargon
establishment of objective attitude towards subject

The correct answers are A. "Omission of contractions", B. "Use of standard English" and E. "Establishment of objective attitude towards subject".

Explanation:

Expository writing is a type of writing that mainly aims at explaining one topic or situation by providing the events, details and any other type of information that is required for the reader to understand the many issue or topic explained this includes newspapers and scientific articles.

Additionally, most expository texts are written in prose rather than in verse and are formal texts, because of this it is recommended these texts are objective, which means they are not based on personal experiences or beliefs but on facts; also, in terms of style these texts should avoid contractions and jargon as these are considered informal and part of speaking but not writing and should use standard English, in this way these are neutral and understood by a broad public. Therefore, the requirements for writing expository prose are the omission of contractions, use of standard English and establishment of objective attitude towards the subject they describe.

taken from the novel “the adventures of huckleberry finn” by mark twain (1884), the author narrates about social issues and norms related to morality, prejudice, and slavery. twain included the excerpt above in order to discuss a moral conflict that huck is in: following the moral values he has received from the society in which he lives. moreover, there are moral issues such as gilt and blame discussed here. in the excerpt above, which is part of chapter xvi, huck faces a dilemma: jim to escape or telling miss watson about jim’s flight. huck feels confused, since by choosing one action or another someone is going to get hurt. both jim and miss watson have him in different ways; jim has protected him and has been very kind with him and miss watson has him with his education. the following sentence is a clear example of the dilemma huck faces when he narrates what his conscience tells him: “what had poor miss watson done to you that you could see her niger go off right under your eyes and never say one single word? ”.