S1 문장의 [______]에 들어갈 단어는?

난이도 고난도 · 힌트를 덜 열수록 높은 점수 (현재 5점)
The most enduring lessons have to be learnt from the seismic response of ground and the built environment in the largest natural [______], i.e., the earth, from damage observations in all earthquakes, whether inter- or intra-plate.