A、A diary. B、A fairy tale. C、A history textbook. D、A biography. D事实细节题。短文一开头，讲话者就说，这里有一本John Muir的传记。由此可见，在接下来的内容中，讲话者会对这本传记进行介绍

Here’s the biography of John Muir. It is John Muir’s own writing to bring readers a life story of this remarkable man who did so much to wake the American awareness of the environmental issue. As America’s first environmentalist, John lives his life for ever daring to undertake new adventures. He spent most of his days outdoors and had deep love for the wildlife. In the book, we meet John Muir who used to fearlessly climb the roof of his house. He captures birds only to let them go when he realizes the cruelty involved. He becomes an inventor and sells his inventions in order to attend the university.(30)As a young man, he began walking over tens of thousands miles during his lifetime, to the south to Florida, the west to California and north to Alaska, where readers are taking a long and particularly hair-raising adventure and on the mass of floating ice. Muir’s learning in observation throughout his life let him devote his last year to preserving the natural environment.(31)His writing and speaking raised awareness of the importance of conservation and helped bring about out national park system. Readers may feel they know John Muir after reading his story and may catch his passion for preserving the richness of our land. The other portrait of Muir’s life has tested many for what means to be lifelong learners and to use that learning to inform and bring about change.
29. What kind of book is the speaker introducing?
30. What do we learn about John Muir when he was young?
31. What did John Muir intend to do through writing and speaking?