11．The"swim-with-dolphins"tourist industry is becoming more popular every year．After all，it can cost a large amount of money to have this kind of holiday experience．So tour operators try to place eager swimmers as near as possible to the dolphins．
Research has shown that dolphins do not like it at all if the swimmers slip into the water directly on top of them or if humans are in their path of travel．However，if swimmers enter the water to one side of them，the dolphins do not avoid the swimmers to the same extent．
In all cases，the dolphins seem to have become more sensitive to the presence of the swimmers．For dolphins，swimming amongst or with humans is not necessarily a high priority．This study has shown that only 19% of any group of dolphins will participate in interaction．Young dolphins are the most likely to interact．It is believed that they see humans as"entertainment"and that the interaction is a new and unusual experience for them．
It is frequently asked whether"swim-with-dolphins"tourism should be discontinued．The advice is that dolphins should be given enough periods of time throughout the day when they are not exposed to tourism．Permitted interactions should not be too disturbing to the dolphins since there could be mothers and calves （幼崽） present in dolphin groups．There should also be educational campaigns about the creatures and what is likely to cause danger to them．
It is not easy to explain to someone that they cannot fulfill their lifelong dreams because the dolphins are resting，or that a mother dolphin and calf are in the area．But if we are to enjoy these remarkable animals and not just use them for our entertainment，then we must carefully monitor the"swim-with-dolphins"industry worldwide．
28．What makes"swim-with-dolphins"tourism popular？D
A．The local government's encouragement．
B．The improvement of people's living standard．
C．The increasing number of tourists．
D．The high profits of the industry．
29．Why are young dolphins more likely to swim with humans？A
A．They do this out of curiosity．
B．They like humans better．
C．They are less sensitive．
D．They are fearless．
30．What should the"swim-with-dolphins"industry do according to Paragraph 4？B
A．Avoid interaction with young dolphins．
B．Make people know the hidden threat to dolphins．
C．Strictly limit the expansion of the industry．
D．Expose dolphins to tourists only in the daytime．
31．What can be inferred from the last sentence of the passage？D
A．The industry has been a hot topic worldwide．
B．The industry aims to bring happiness to humans．
C．The industry enables humans to swim with dolphins．
D．The industry will harm dolphins without proper control．
分析 本文属于说明文阅读，作者通过这篇文章主要向我们描述了"海豚游"旅游业正变得越来越流行，但如果控制不当，这会对人类和海豚双方造成危害．
解答 28．D．细节理解题．根据第一段After all，it can cost a large amount of money to have this kind of holiday experience．So tour operators try to place eager swimmers as near as possible to the dolphins可知行业的高利润使"海豚游"流行；故选D．
29．A．细节理解题．根据第三段Young dolphins are the most likely to interact．It is believed that they see humans as"entertainment"and that the interaction is a new and unusual experience for them可知年轻海豚更容易与人类游泳因为处于好奇；故选A．
30．B．细节理解题．根据第四段There should also be educational campaigns about the creatures and what is likely to cause danger to them可知建议"海豚游"行业应该让人们知道海豚隐藏的威胁；故选B．
31．D．推理判断题．根据最后一段But if we are to enjoy these remarkable animals and not just use them for our entertainment，then we must carefully monitor the"swim-with-dolphins"industry worldwide可知如果没有适当的控制，这个行业会危害海豚；故选D．
点评 考察学生的细节理解和推理判断能力，做细节理解题时一定要找到文章中的原句，和题干进行比较，再做出正确的选择．在做推理判断题不要以个人的主观想象代替文章的事实，要根据文章事实进行合乎逻辑的推理判断．
