Which sentence should be removed from the conclusion?

(1) year-round schooling would student achievement. (2) not so much information would have to be crammed into nine months. (3) furthermore, the elimination of long breaks, particularly summer break, would significantly reduce "learning loss” and the additional time wasted at the beginning of each academic year to reteach previously learned material. (4) it is clear that year-round schooling students learn and retain more. (5) the united states is not the only country to experiment with a year-round school schedule. (6) although many still claim that evidence about year-round school and its link to higher achievement is inconclusive, these people need to open their eyes and see that students in these schools consistently score higher on certain assessments than students who attend schools with traditional nine-month calendars. (7) it is about time that we replaced our outdated and inefficient school calendars.

sentence 1
sentence 3
sentence 5
sentence 7