Why should sentence 4 be removed from this conclusion? it criticizes those who disagree with the writer. it strengthens the viewpoint of the opposition. it states a fact that is unrelated to the topic. it unnecessarily restates the editorial’s claim.

Sentence 4 should be removed from this conclusion because it unnecessarily restates the editorial's claim. The opening sentence states "year-round schooling would help student achievement" and then sentence 4 restates "it is clear that year-round schooling helps students learn and retain more".  The conclusion is what you leave to the reader, it wraps around your essay, it shows that you have proved your thesis. You should summarize what you have written about in your paper but you should avoid simply restating your thesis statement as it is redundant.

It unnecessarily restates the editorial’s claim.

Explanation:

It unnecessarily restates the editorial’s claim.

active voice: my father cut the tree.

passive voice: the tree was cut by my father.

active voice: people buy newspapers every day.

passive voice: newspapers are bought (by people) every day.

active voice: people have been using movies as political propaganda since world war ii.

passive voice: movies have been used as political propaganda since world war ii.

active voice: donna gave me my birthday present.

passive voice: i was given my birthday present (by donna). / my birthday present was given to me (by donna).

active voice: mom will leave the keys on the counter.

passive voice: the keys will be left (by mom) on the counter.

the words in parentheses are the agent of the passive voice and can be omitted when obvious, generic, or simply unnecessary.