A、They are newer than the formations in most caves. B、They were formed by sulfuric acid. C、They have been artificially preserved

Hello, everybody, I am here, because I visited caves all over North America. Since you are going to study cave formations, Dr. Bow asked me to come and share some of my experiences with you. In additional to describing some of the technical aspects of the caves, I would convey the sense of adventure that cavers share. Recently, I visited the La Chagire cave in New Mexico, my dream has always been to discover a new passage way.  I had a chance here, because La Chagire is so large that discoveries are frequently made there. The cave itself was not even discovered until 1986. However, people in that area had figured that there must be a cave nearby, because of the strong wind that blew from behind the huge rock that covered the entrance. Enormous amounts of air enter and exit the cave in order to maintain balance of the pressure with the side air. When I climbed into the cave, I had to fight 45 mile per hour winds. After all that effort, I had to be extremely careful maintaining my energy level. People who are tired tend to be careless, and may be more concerned about getting out of the cave than taking care of it. There are formations in LaChagire that look like ocean waves, Christmas trees and other stuff no one has ever seen before. Caves are normally created by carbonic acid that trickles down from above, but this cave sculpted out by very powerful sulfuric acid that wells up from below.