div class=ts-pagebutton class=gotoPage data-page=1Page 1button div class=ts-imageimg data-url=tf-1999-exploring-caves-1-ost-american-caves-are-big-holes-that-form-in-limestonehtmlpage=1 data-page=1 class=ts-thumb lazyload alt=Page 1: TF 1999 Exploring Caves 1€¦ · ost American caves are big holes that form in limestone rock The holes begin as cracks in the limestone Water flows down the cracks and dissolves loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader033vdocumentinreader033viewer20220428125faf38776cdeda2c091ab5ffhtml5thumbnails1jpg width=140 height=200 divdivdiv class=ts-pagebutton class=gotoPage data-page=2Page 2button div class=ts-imageimg data-url=tf-1999-exploring-caves-1-ost-american-caves-are-big-holes-that-form-in-limestonehtmlpage=2 data-page=2 class=ts-thumb lazyload alt=Page 2: TF 1999 Exploring Caves 1€¦ · ost American caves are big holes that form in limestone rock The holes begin as cracks in the limestone Water flows down the cracks and dissolves loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader033vdocumentinreader033viewer20220428125faf38776cdeda2c091ab5ffhtml5thumbnails2jpg width=140 height=200 divdivdiv class=ts-pagebutton class=gotoPage data-page=3Page 3button div class=ts-imageimg data-url=tf-1999-exploring-caves-1-ost-american-caves-are-big-holes-that-form-in-limestonehtmlpage=3 data-page=3 class=ts-thumb lazyload alt=Page 3: TF 1999 Exploring Caves 1€¦ · ost American caves are big holes that form in limestone rock The holes begin as cracks in the limestone Water flows down the cracks and dissolves loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader033vdocumentinreader033viewer20220428125faf38776cdeda2c091ab5ffhtml5thumbnails3jpg width=140 height=200 divdivdiv class=ts-pagebutton class=gotoPage data-page=4Page 4button div class=ts-imageimg data-url=tf-1999-exploring-caves-1-ost-american-caves-are-big-holes-that-form-in-limestonehtmlpage=4 data-page=4 class=ts-thumb lazyload alt=Page 4: TF 1999 Exploring Caves 1€¦ · ost American caves are big holes that form in limestone rock The holes begin as cracks in the limestone Water flows down the cracks and dissolves loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader033vdocumentinreader033viewer20220428125faf38776cdeda2c091ab5ffhtml5thumbnails4jpg width=140 height=200 divdiv