听力音频：

• Preparation for fieldwork trip to Namibia in 31. ______
• Earliest explanation of engravings of animal footprints were used to help 32. ______ learn about tracking
• Why are the tracks usually 33. ______?
• Why are the unrealistic animals sometimes half 34. ______?
• Wise men may have been trying to control wild animals with 35. ______

• If you look at a site from a(n) 36. ______ you reduce visitor pressure
• To camp on a site may be disrespectful to people from that 36. ______
• Undiscovered material may be damaged by 38. ______
• You should avoid 39. ______ or tracing rock art as it is so fragile
• Your aim is to leave the site 40. ______

答案