Among 168 earth samples, visitors can examine a specimen of 2.7 billion-year-old rock from Ontario, Canada, bearing the different bands of iron that help scientists determine the age of mountains and other land formations.
(scientists; determine; the age of mountains and other land formations) (visitors; can examine; a specimen of 2.7 billion-year-old rock from Ontario; L:Among 168 earth samples) Context(visitors can examine,List([25, 45))):(visitors; can examine a specimen of 2.7 billion-year-old rock from Ontario bearing; the different bands of iron)
visitors can examine,List([25, 45))
scientists visitors visitors
determine can examine can examine a specimen of 2.7 billion-year-old rock from Ontario bearing
the age of mountains and other land formations
a specimen of 2.7 billion-year-old rock from Ontario L:Among 168 earth samples
the different bands of iron