모의고사 어법 문제인데 답만 있고, 해설이 없어서 질문합니다....
1번
the u. s. space agency nasa is currently on the hundred years starship, a project of exploring new habitable planets and ①helping people settle down there. if settlers succeed in making ②another planet their home, it will become one of the most revolutionary events in history. ③assumed to have a substantial amount of water, mars is probably most habitable out of all the planets in our solar system. however, this project would take time since the cost will make a return flight to earth almost ④impossible. although the living supplies for the settlers would ⑤send from earth, taking the risk of exchanging life for dreams is tough.
5번이 답인데, send를 be sent 로 고치면 맞는건가요?2번
“my secret is hidden within me; my name no one shall know.” those are the words, roughly translated, from the famous puccini aria nessun dorma. you have probably heard luciano pavarotti sing it once or twice. but it has never had so much meaning as it (a) [did / was] on a stage in great britain, being sung by a mobile phone salesman named paul potts. potts is an average-looking man (b) [his / whose] teeth are not straight. he admits to having battled self-confidence issues for his whole life. still, he decided to audition for a television show. then, he made it. we all have a passion, a secret buried within us. and yes, for the most part, the world will never know our names. but that does not mean we haven’t made an impact, changed lives for the better, or (c) [had / have] a meaningful life on this planet. find your inner paul potts. everyone has one.

a의 답이 did 인데, 여기서 did 는 did have so much meaning을 받는 대동사인가요???

3번
while we don’t all have the same amount of money, we do have access to the same twenty four hours in every day. though some people have ①much less free time than others, nearly everyone has some opportunity to give. the gift of time can sometimes be more ②satisfied and more valuable than money. you can see this by watching those who have volunteered at homeless shelters or ③brought meals on wheels to seniors. if you are willing to volunteer, there are many organizations and projects ④that will be glad to welcome you. ⑤whatever you do, it will almost certainly be educational, enjoyable, and rewarding.
2번이 답인데, the gift of time 이 만족을 주는거니까 satisfying으로 고치는게 맞나요??감사합니다.