Read the excerpt from Studies of Trees, by Jacob Levison. The pines are widely distributed throughout the Northern Hemisphere, and include about 80 distinct species with over 600 varieties. The species enumerated here are especially common in the eastern part of the United States, growing either native in the forest or under cultivation in the parks. The pines form a very important class of timber trees, and produce beautiful effects when planted in groups in the parks. Which strategy does the author use in his choice of language to convey his message