Reading comprehension is an important contents in english learning, and is classified 7 types according to various forms of passage, including the main theme of the passage, the central idea of the passage, the main purpose of the article, the author's attitude toward the article, forms of literature on the article, to guess the meaning of words from its context, to realize and grasp the detail of paragraph. Fist we will do the following training about the main theme of article.

　Exercises One

　　Linnaeus' enormous and essential contribution to natural history was to devise a system of classification whereby any plant or animal could be identified and slotted into an oven plan. In creating this system, Linnaeus also introduced a method of naming biological special that is still used today. Three two innovations may sound unexciting until one tries to imagine a scientific world without these fundamental tools-as was indeed the case with natural history before the Linnaeuan system.
　　Previous naturalists (and Linnaeus himself in his youth) had tried to name species by listing all of a species' distinguishing features. Often these multiword names had to be expanded when similar related species were discovered, and the names differed from author to author and language to language. Naturalists therefore had difficulty understanding and building on one another'work. It became crucial that every special have the same name in all languages. In using Latin for naming species, Linnaeus followed the custom of his time, but in reduing the name of each species to two words--the genus, common to every species within the genus, and the species name itself he made an invaluable break with the past. For instance, a shell with earlier names such as "Marbled Jamaica Murex with Knotty Twirls (Petiver)" became simply Strombus gigas L ("L" for Linnaeus).
　　Yet the invention of a system of naming species, vital as it has come to seen, was trival by comparison with Linnaeus' main achievement: devising a classification system for all organism, so that scientists no longer had to list every species individually. Linnaecus' universally understood classification of species also enabled scentists to retrieve information, make predictions, and understand traits by association. Linnaeus divided each kingdom (animal, vegetable, and mineral) into hierarchies that are still, with some additions, followed today. His classifications reflect an eighteenth-century concept of nature in which all organisms,graded form lower to higher, formed a ladder or "great chain of being," with the human species at the summit.
　　Linnaeus himself would probably have been the first to admit that classification is only a tool, and not the ultimate purpose, of biological inquiry. Unfortunately, this truth was not apparent to his immediate successors, and for the next hundred years biologists were to concern themselves almost exclusively with classification. All facts, however trival, were greatly valued; all theories,however stimulating, were avoided. And the facts with which these naturalists were most concerned were those bearing on the description and classification of species.