GRE Reading Comprehension: JiJing 352-GRE阅读机经352篇 - KS5C7D6H87AB4CI4K

A photograph from 1843 is sometimes claimed to be the earliest surviving portrait of Abraham Lincoln (1809-1865), sixteenth President of the United States. The photograph shows a face without a cleft chin, whereas Lincoln's chin was cleft. However, since skilled retouching of a photographic negative can undetectably change a feature such as a cleft chin in portraits produced from the negative, absence of a cleft chin is inconclusive as evidence that the photograph is no Lincoln.