that is why when we approach a traffic light we do not have to think everything through as if it were the first one we ever saw.
human beings seek and require a certain degree of stability in thought and action without which we simply could not survive. ( ① ) our cognitive abilities allow us to establish conditioned or learned responses to the situations we confront on a continual basis. ( ② ) we do not need to reinvent the wheel each time we act, so to speak. ( ③ ) we know, or assume we know, that red means stop, green means go, and yellow means slow down and proceed cautiously. ( ④ ) the templates in our minds also tell us that applying pressure to the gas pedal will make us go faster and applying pressure to the brake will slow us down. ( ⑤ ) we also believe from the mental pictures we have previously developed that other drivers will behave in predictable manners as well.

윗글이 문제집 원문 입니다~
일단 답은 3번 입니다. 삽입해야할 문장의 that is why ~의 that이 we do not need to reinvent the wheel each time we act, so to speak.를 언급하고 3번 이하문장이 예시로서 나온다고 나와있는데요..
제가 궁금한것은 주어진 문장이 4번에도 들어갈수 있지 않을까... 하는 의문입니다~
안된다면.. 왜 안돼는지.. 궁금합니다~