5번.walton motors has requested thousands of consumers in an online survay to describe _____ their requirements are when buying an automobile. 

제가 알기론 성택범위가 있을때는 which를 쓰고 선택범위가 없을때는 what을 쓰는걸로 알고있는데 여기엔 automobile이라는 선택범위가 있는거 아닌가ㅛ??근데 왜 what이 답일까요..??

6번.with only one month left until the hotel`s grand opening,the owner must decide ___

chef he wants to hire for the restaurant.

빈칸뒤가 완전한 문장이라서whom 이라고 생각했는데 왜which일가요..?? which+명사+불완전

문장인데  which+명사해도 뒤에 완전한 문장 되는거 아닌가요...???

7번,carlton smith told us to contact the travel agent and book ___ flight ticket was cheapest.

답이 whichever인데 whichever다음엔 불완전 문장오는거 아닌가요..???이건 완전한문장인데...

왜그런걸까요..??

23번. complimentary t-shirts will be given to___ registers for the trade fair by april 9.

에서 동사가 하나인것같은데 왜 접속사를 쓰는거죠..???

답은 whoever입니다..

29번.george jones did not mention ___ article would be published in next month`s issue.

해석상으로도 문장구조로도 when,whose 다 되는것 같은데 왜 답은 whose일까요..???

알려주세요!!!!!