31. perhaps nothing is as surprising to the observer as the of the grand canyon.

1) yet vast intricate landscape
2) vast yet intricate landscape

정답이 2번이라는데 두 답의 차이가 뭔지, 왜 2번인지 설명 부탁드립니다.

45. b) 대화문에서 틀린 부분 찾아주세요.
a) you just discovered them? you had never been in her attic before?
b) yes. but hidden behind furniture, i never realized they were up there.
hidden 앞에 분사의 의미상의 주어가 빠졌기 때문일거라고 생각합니다. they hidden이라고 생각하는데 맞을까요?