1.Petrography concerns primarily with the detailed description and classification of rocks, whereas petrology deals primarily with rock formation .





2.A large collections of materials focused on Louisiana�s history and culture is provided by the Williams Research Center in New Orleans.





3.Mary Austin�s first book, The Land of little Rain, a description of desert life in the western United States, won she immediate fame in 1903.





4.The most abundant phosphate mineral, apatite, includes several type that vary in their content of fluorine, chlorine, or hydroxyl ions.





5.Having gained a reputation as a daring, intrepid journalist, Nellie Bly became the first female report assigned to the Eastern front during the First World War.





6.In 1862 Abraham Lincoln signed the Homestead Act, allows settlers 160 acres of free land after they had worked it for five years.





7.Alone with the other physical sciences, meteorology has developed in the past three centuries from myth and folklore to rigorous observation , computation, analyze .





8. In 1973 the United States armed forces were placed on an all-volunteer basis for a first time since 1984.





9.Because lions do not have exceptional speedy , they must rely on the element of surprise for the hunt .





10.The position of the earth�s magnetic poles is not constant but shows an appreciable change after year to year.