The Earth is an incredible planet filled with natural, ancient, and modern-day wonders. From the sacred Mt. Fuji of Japan to the stunning Inca citadel of Machu Picchu to the Christ the Redeemer in Brazil, these sites inspire awe and __1__ us with our past. Another such site famous for its interactive quality is the Great Blue Hole in Belize. Known as the largest sea hole in the world, it is a perfectly __2__ oceanic sinkhole measuring 300 meters wide and 125 meters deep. Located about 70 kilometers from Belize City, it is one of the many sea holes that dot the ocean. Before it became a sea hole, however, it was a cave. This status changed when its roof __3__ due to the rising sea level at the end of the last great Ice Age more than 10,000 years ago. The Great Blue Hole is a UNESCO World Heritage Site, a __4__ it shares with the other wonders previously mentioned.
Although it is a breathtaking view to behold, it can also be __5__. The water in the Great Blue Hole is crystal clear, which makes it harder for divers and swimmers to __6__ distance and depth properly. Divers are tricked into thinking they are much closer to the bottom than they actually are. They find themselves going deeper than they intended to and then __7__ air before they can get back to the surface.
The area is also __8__ sharks. Caribbean reef sharks are common there, and divers must be __9__ of their surroundings at all times. Other shark species, such as bull sharks and hammerheads, have also been sighted. For these reasons, snorkelers can explore the reefs, but only __10__ divers with at least 24 dives under their belt may be allowed to go diving there.
答案：1.D 2.G. 3.F 4.I 5.B 6.A 7.J 8.H 9.E 10.C