Life originated in the early seas less than a billion years after Earth was formed.

            Yet another three billion years were to pass before the first plants and animals appeared

            on the continents. Life's transition from the sea to the land was perhaps as much of an

 Line     evolutionary challenge as was the genesis of life.

  (5)          What forms of life were able to make such a drastic change in lifestyle ? The

            traditional view of the first terrestrial organisms is based on megafossils ― relatively

            large specimens of essentially whole plants and animals. Vascular plants, related to          

            modern seed plants and ferns, left the first comprehensive megafossil record. Because

            of this, it has been commonly assumed that the sequence of terrestrialization reflected

 (10)      the evolution of modern terrestrial ecosystems. In this view, primitive vascular plants

            first colonized the margins of continental waters, followed by animals that fed on the          

            plants, and lastly by animals that preyed on the plant-eaters. Moreover, the megafossils

            suggest that terrestrial life appeared and diversified explosively near the boundary

            between the Silurian and the Devonian periods, a little more than 400 million

 (15)      years ago.

                Recently, however, paleontologists have been taking a closer look at the sediments

            below this Silurian-Devonian geological boundary. It turns out that some fossils can be       

            extracted from these sediments by putting the rocks in an acid bath.The technique has         

            uncovered new evidence from sediments that were deposited near the shores of the

 (20)      ancient oceans ― plant microfossils and microscopic pieces of small animals. In many

            instances the specimens are less than one-tenth of a millimeter in diameter. Although

            they were entombed in the rocks for hundreds of millions of years, many of the fossils

            consist of the organic remains of the organism.

                These newly discovered fossils have not only revealed the existence of previously

 (25)      unknown organisms, but have also pushed back these dates for the invasion of land by

            multicellular organisms. Our views about the nature of the early plant and animal              communities are now being revised. And with those revisions come new speculations

            about the first terrestrial life-forms.

 

            28. The word “drastic” in line 5 is closest in meaning to

              (A) widespread

              (B) radical

              (C) progressive

              (D) risky

 

            29. According to the theory that the author calls “the traditional view,” what was the                 

                first form of life to appear on land?

              (A) Bacteria       

            (B) Meat-eating animals

              (C) Plant-eating animals

            (D) Vascular plants

 

            30. According to the passage, what happened about 400 million years ago?

              (A) Many terrestrial life-forms died out.

              (B) New life-forms on land developed at a rapid rate.

              (C) The megafossils were destroyed by floods.

              (D) Life began to develop in the ancient seas.

 

 

            31. The word “extracted” in line 18 is closest in meaning to

              (A) located

              (B) preserved

              (C) removed

              (D) studied

 

            32. What can be inferred from the passage about the fossils mentioned in lines 17-20 ?

              (A) They have not been helpful in understanding the evolution of terrestrial life.

              (B) They were found in approximately the same numbers as vascular plant fossils.

              (C) They are older than the megafossils.

              (D) They consist of modern life-forms.

 

            33. The word “instances” in line 21 is closest in meaning to

              (A) methods

              (B) processes

              (C) cases

              (D) reasons

 

            34. The word “they” in line 22 refers to

              (A) rocks

              (B) shores

              (C) oceans

              (D) specimens

 

            35. The word “entombed” in lime 22 is closest in meaning to

              (A) crushed

              (B) trapped

              (C) produced

              (D) excavated

 

            36. Which of the following resulted from the discovery of microscopic fossils?

              (A) The time estimate for the first appearance of terrestrial life-forms was revised.

              (B) Old techniques for analyzing fossils were found to have new uses.

              (C) The origins of primitive sea life were explained.

              (D) Assumptions about the locations of ancient seas were changed.

 

            37. With which of the following conclusions would the author probably agree?

              (A) The evolution of terrestrial life was as complicated as the origin of

                life itself.

              (B) The discovery of microfossils supports the traditional view of how terrestrial

                life evolved.

              (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 about ages of fossils.