Read the passages and choose the best answer to each question. Answer all questions about a passage on the basis of what is stated or implied in that passage.
Time – 15 minutes
JOHNNY APPLESEED
2. Chapman spent forty years wandering as Johnny Appleseed. Journeying by foot and canoe through Ohio and Indiana, he planted seeds, sold and gave away apple saplings, and exchanged knowledge of medicinal plants with Indians and settlers. He prepared the way for farms and towns by planting apple seeds in clearings along rivers and constructing simple wooden fences to keep animals out of his primitive orchards.
3. The agricultural development that Chapman anticipated was in fact marching across the eastern half of the continent at an ever–increasing pace. When Chapman started his “apple seeding” in 1801, the population of Ohio was 45,000, and ninety percent of the land was still covered with elm, ash, maple, oak, and hickory trees. By the time of Chapman’s death in 1845, the state’s population had reached two million, and more than forty percent of the land had been cleared of trees and converted to farms. Not until 1880 did the cutting of trees subside. By then, three–quarters of Ohio had been cleared, and people were becoming aware of the limits of expansion. Only then did they begin to take seriously the tree–loving ideas of Johnny Appleseed, who had become the subject of folk tales.
THE ORIGIN OF THE UNIVERSE
2. The original universe underwent a physical transition that gradually differentiated it into galaxies, stars, and planets. As the original mass of gas expanded and cooled, large clouds separated themselves from the parent mass. Gravity played an important role in this mechanism. Matter is subject to gravity, yet matter is also the cause of gravity since it is matter’s mass that determines the strength of the gravitational force.
3. Scientists believe that the original mass of gas in the universe was not completely uniform, and there were some regions that were slightly denser and capable of generating stronger gravitational fields than others. Since gravity tends to pull matter together, the denser regions tended to become even more compact. Thus, small variations in the original mass evolved into denser clouds that gradually separated from the expanding parent mass. From these clouds, the galaxies were formed.
4. At the end of the first phase of the universe, a great number of huge clouds had become separate entities that could start their own independent evolution. These turbulent clouds— ancient galaxies—contained variations that grew in importance over time. The clouds divided into smaller and smaller “cloudlets” that gravity caused to contract. The increase in pressure from this contraction caused the temperature to rise until the cloudlets began to glow as individual, luminous stars.
5. Astronomers believe that the earliest galaxies were small when they formed most of their stars, but accumulated most of their mass later through collisions. Large galaxies formed in stages as smaller galaxies were attracted to one another by gravity. As the smaller galaxies were pulled together over time, they merged into larger and larger structures, eventually forming massive galaxies. As many as half of all galaxies are thought to have been involved in some sort of collision.
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