Original sentence: David Spindler is an independent American scholar of the Great Wall of China and is one of its leading researchers.David has spent the last nine years researching the Great Wall.He attended Dartmouth College and Harvard Law School, and spent two years as a consultant at McKinsey & Company.He was recently profiled in an article in The New Yorker
Edited sentence: David Spindler is an independent Scholar of the Great Wall of China, and is one of it's leading researchers.David has spent the last 9 years researching the Great Wall of China.He attended Dartmouth College and Harvard Law School, David spent two years as a consultant at McKinsey & Company.He was recently profiled in an excellent article in The New Yorker.The Great Wall is one of the existing megastructures and the world's longest human-made structure, stretching over approximately 6,400 km (4,000 miles) from Shanhai Pass in the east to Lop Nur in the west, along an arc that roughly delineates the southern edge of Inner Mongolia.Walking the Wall, The New Yorker, May 21 2007 issue written by Peter Hessler.— Letter From China