영화 up 의 줄거리를 해석해야하는데 해석이 어려운 부분이 있어서 질문을 드리게됐네요!!

young carl fredricksen is a shy, quiet boy who idolizes renowned explorer charles f. muntz he is saddened to learn, however, that muntz has been accused of fabricating the skeleton of a giant bird he had claimed to have discovered in paradise falls, south america. muntz vows to return there to capture one alive. one day, carl befriends an energetic and somewhat eccentric tomboy named ellie, who is also a muntz fan. she confides to carl her desire to move her clubhouse—an abandoned house in the neighborhood—to a cliff overlooking paradise falls, making him promise to help her. carl and ellie eventually get married and grow old together in the restored house, working as a toy balloon vendor and a zookeeper, respectively. unable to have children, they repeatedly pool their savings for a trip to paradise falls, but end up spending it on more pressing needs. an elderly carl finally arranges for the trip, but ellie suddenly becomes ill and dies, leaving him alone.
years later, carl still lives in the house, now surrounded by urban development, but he refuses to sell. he ends up injuring a construction worker over his damaged mailbox. as a result, he is evicted from the house by court order and ordered to move to a retirement home. however, carl comes up with a scheme to keep his promise to ellie: he turns his house into a makeshift airship, using thousands of helium balloons to lift it off its foundations. a young wilderness explorer named russell becomes an accidental passenger, having pestered carl earlier in an attempt to earn his final merit badge, assisting the elderly.1.he is saddened to learn, however, that muntz has been accused of fabricating the skeleton of a giant bird he had claimed to have discovered in paradise falls, south america.
여기에 쓰인 that은 무슨역활을 하죠? 그는 배우는게 슬펐다. ?? 하지만, muntz는 그가 남미의 파라다이스 폭포에서 발견했다고 주장하는 큰 새의 뼈가 날조됐다는 비난을 받아왔다,2.he turns his house into a makeshift airship, using thousands of helium balloons to lift it off its foundations
그는 그의 집을 일시적인 방편으로 비행선으로 바꿨고 ,근본적으로 집을 뜨게하기 위해서 헬륨풍선을 수천개를 사용했다. 3.she confides to carl her desire to move her clubhouse—an abandoned house in the neighborhood—to a cliff overlooking paradise falls, making him promise to help her.
그녀는 carl에게 클럽하우스를 파라다이스 폭포가보이는 절벽으로 옮기고 싶음을 말했고, 그가 그녀를 도와주겠다는 약속을 하게 했다. (클럽하우스는 이웃에 버려진 집)

4.a young wilderness explorer named russell becomes an accidental passenger, having pestered carl earlier in an attempt to earn his final merit badge, assisting the elderly.
russell 이라 불리는 어린 자연보호 탐험가 가 우연적으로 승객이 되었고,이아이는 마지막 벳찌인 노인봉사 공로 벳찌를 얻기위해 carl을 귀찮게 했다.?