- 問題詳情: Mostofthetime,thegroundfeelssolidbeneathourfeet.That'scomforting.Butit'salsomisleadingbecausethere'sactuallyalotgoingonunderground.Massesofland(calledplates)slip,slide,andbumpagainsteachother,slowlychangingtheshapeofcontinentsandoceans...
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