[ Pobierz całość w formacie PDF ]
.(C) New species have appeared at the same rate over the course of the last 400 million years.(D) The technology used by paleontologists is too primitive to make accurate determinations aboutages of fossils.1997-12Questions 32-40Fossils are the remains and traces (such as footprints or other marks) ofancient plant and animal life that are more than 10,000 years old.They range insize from microscopic structures to dinosaur skeletons and complete bodies ofenormous animals.Skeletons of extinct species of human are also considered(5) fossils.An environment favorable to the growth and later preservation oforganisms is required for the occurrence of fossils.Two conditions are almostalways present: (1) The possession of hard parts, either internal or external, suchas bones, teeth, scales, shells, and wood; these parts remain after the rest of theorganism has decayed.Organisms that lack hard parts, such as worms and jelly(10) fish, have left a meager geologic record.(2) Quick burial of the dead organism, sothat protection is afforded against weathering, bacterial action, and scavengers.74Dedication Innovation Professionalism EQuest Academy Joint Stock CompanyAdd: 44 Hang Chao, Dongda, HanoiTel: 84-4-823 6151 Fax: 84-4-823 6151Email: EQA@EQuest.edu.vn Website: www.EQuest.edu.vnNature provides many situations in which the remains of animals and plants areprotected against destruction.Of these, marine sediment is by far the mostimportant environment for the preservation of fossils, owing to the incredible(15) richness of marine life.The beds of former lakes are also prolific sources offossils.The rapidly accumulating sediments in the channels, floodplains, anddeltas of streams bury fresh-water organisms, along with land plants and animalsthat fall into the water.The beautifully preserved fossil fish from the Green Riversoil shale of Wyoming in the(20) western United States lived in a vast shallow lake.The frigid ground in the farnorth acts as a remarkable preservative for animal fossils.The woolly mammoth,along-haired rhinoceros, and other mammals have been periodically exposed inthe tundra of Siberia, the hair and red flesh still frozen in cold storage.Volcanoes often provide environments favorable to fossil preservation.(25) Extensive falls of volcanic ash and coarser particles overwhelm and bury all formsof life, from flying insects to great trees.Caves have preserved the bones of manyanimals that died in them and were subsequently buried under a blanket of clay ora cover of dripstone.Predatory animals and early humans alike sought shelter incaves and brought food to them to the eater, leaving bones that paleontologistshave discovered.32.The passage primarily discusses which of the following?(A) Types of fossils found in different climates(B) What is learned from studying fossils(C) Conditions favorable to the preservation of fossils(D) How fossils are discovered33.The word "traces" in line 1 is closest in meaning to(A) structures(B) importance(C) skeletons(D) imprints34.All of the following facts about fossils are refereed to by the author (paragraph 1) EXCEPT thefact that they can be(A) microscopically small(B) skeletons of human ancestors(C) complete animal bodies(D) fragile35.The fossil fish from the Green River (paragraph 3) were probably preserved because they were(A) in a deep lake(B) covered by sediment(C) protected by oil(D) buried slowly36.The word "exposed" in line 22 is closest in meaning to(A) photographed(B) uncovered(C) located(D) preserved75Dedication Innovation Professionalism EQuest Academy Joint Stock CompanyAdd: 44 Hang Chao, Dongda, HanoiTel: 84-4-823 6151 Fax: 84-4-823 6151Email: EQA@EQuest.edu.vn Website: www.EQuest.edu.vn37.Which of the following is LEAST likely to be found as a fossil, assuming that all are buried rapidly?(A) a dinosaur(B) a woolly mammoth(C) a human ancestor(D) a worm38.It can be inferred that a condition that favors fossilization when volcanic ash falls to Earth is(A) quick burial(B) cold storage(C) high temperature(D) lack of water39.The word "them" in line 29 refers to(A) predatory animals(B) early humans(C) caves(D) bones40.Which of the following is true of the environments in which fossil are found?(A) Very different environments can favor fossilization.(B) There are few environments in which fossils are protected.(C) Environments that favor fossilization have similar climates.(D) Environments that favor fossilization support large populations of animals.1998-08Questions 21-30Anyone who has handled a fossilized bone knows that it is usually not exactlylike its modern counterpart, the most obvious difference being that it is often muchheavier.Fossils often have the quality of stone rather than of organic materials, andthis has led to the use of the term "petrifaction" (to bring about rock).The implication is(5) that bone and other tissues have somehow been turned into stone, and this is certainlythe explanation given in some texts.But it is a wrong interpretation; fossils arefrequently so dense because the pores and other spaces in the bone have becomefilled with minerals taken up from the surrounding sediments.Some fossil bones haveall the interstitial spaces filled with foreign minerals, including the marrow cavity, if there(10) is one, while others have taken up but little from their surrounding
[ Pobierz całość w formacie PDF ]