21.细节理解题,根据 Mendenhall Glacier中的“Another benefit is the finding of large block of land thickly covered with ancient trees"可得答案22.D细节理解题。根据 Perito Moreno Glacier部分中的There're also boat rides along the glacier lake to take closer look and helicopter rides that give truly unique and unforgettable experience可知答案23.D推理判断题,根据 Furtwangler Glacier部分中的“It is estimated that it will completely melt by2020和 Pasterze Glacier中的 Very soon this glacier may completely melt away”可得答案24.D推理判断题,根据第一段中的“ hadn't' been planning to sell the company,'she says.Over the years we had meetings with prospective buyers, but we wanted to keep doing what we were doing"案