美国有线新闻 CNN 2013-03-06(在线收听

 First up today on CNN student news. This Florida resident was in his bedroom last Thursday. Suddenly the ground underneath opened up and swallowed him. A sinkhole about 20 feet wide and 40-50 feet deep, formed underneath Jeff Bush's room. His brother Jeremy talked about what happened when it started.

"I heard a loud crash like car came into the house, and I heard my brother screaming, so I ran back there and tried going inside the room, but when I later turned the light on, all I see was a big hole, a big hole."
Jeremy Bush jumped into that hole to try to save his brother, but he couldn't find him. Officials called off their search on Saturday, partly because of the same reason why workers begin demolishing the house. The sinkhole was expanding, and there were concerns the house might collapsed at any time. Sometimes sinkholes are smaller, they might cause the ground to sag or cause a small pond to form. Other times, they can be huge, like this one you're looking at right now from Guatemala, or the great blue hole, an underwater sinkhole off the coast of Belize.
Florida actually gets a lot of sinkholes, that's because of the ground across a lot of the state is made up of limestone, a sedimentary rock. Nick Valencia explains how that can lead to the sinkhole.
How do sinkholes form? Well, let's break this down for you here. Sinkholes are usually a naturally occuring event, then what happens is that rain water, that heavy rain water, sort of sits on top of that bedrock sanding clay. If you taken to account Florida's landscape, it has got a lot of that of very porous limestone, that allows the rain, the acidic rain to sort of percolated down into the soil, forming these cave like sinkholes here. And also, sometimes, it's drought that causes these cave-like formations. And that's further the punctuated by that heavy rain that sort of sits on top of there causing this to open up and perhaps some of the scarest scenarios, that in Florida is that, you can not predict sinkholes, it's highly expensive to predict them yet, you have to use very expensive equipment. And it's really tough to pinpoint where these sinkholes are. In fact, it's so common about the currents in Florida, all of these little blue dots from freckled upon and down the state of Florida. Our past instances of sinkholes, now what happened on Thursday night and early Friday morning in Hillsboro County at the Bush residents, this is the place that the Florida department of state says is a susceptible to abruptly forming collapse sinkholes, it's an area that's dominated by an area that's had problems with sinkholes in the past.
  原文地址:http://www.tingroom.com/lesson/cnn2013/3/234048.html