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Directions: You have 20 minutes to plan and write your response. Your response will be judged on the basis of the quality of your writing and on how well your response presents the points in the lecture and their relationship to the
reading passage. Typically, an effective response will be 150 to 225 words.
Summarize the points made the lecture. Then, be sure to explain how they respond to the specific arguments presented in the reading passage.
题目原文：
Orcas are large predatory whales whose typical coloration is mostly black with some white patches. In recent years, however, sightings of an unusual, almost completely white orca have been reported in the northern Pacific Ocean. One sighting of a white orca occurred near Alaska in 2000. Another sighting of a white orca nicknamed Iceberg by scientists was made off the coast of Russia in 2010.
Because a white orca is so unusual, some scientists have suggested that Iceberg, the whale seen off the coast of Russia, was the same animal as the orca seen earlier near Alaska. However, there are convincing arguments that Iceberg and the Alaskan white orca are actually two different individuals.
Slight Coloration Differences
First, although all the photographs made during the sightings show very light-colored animals, the orca seen in Alaska appears to be just slightly darker than Iceberg. Such differences in coloration suggest that these were two distinct animals that were independently sighted in the northern Pacific.
Sightings Far Apart
Second, the sightings were very far apart. The Alaskan orca was seen near the central Aleutian Islands, a long string of islands that extends westward from the mainland of Alaska. Iceberg was seen near the Commander Islands, off the coast of Russia. More than 1,500 kilometers separate the two locations. Typically, orcas tend to stay near the mainland coast and not travel such long distances.
Age Estimates
Third, when scientists saw the Alaskan white orca in 2000, they estimated that it was around twenty years old, based on the size of its dorsal (back) fin. When researchers saw Iceberg, their estimate of its age, based on the fin size, was also around twenty years but that was in 2010, when the Alaskan orca would have been thirty! The estimates again suggest quite strongly that these are two different individuals.
Because a white orca is so unusual, some scientists have suggested that Iceberg, the whale seen off the coast of Russia, was the same animal as the orca seen earlier near Alaska. However, there are convincing arguments that Iceberg and the Alaskan white orca are actually two different individuals.
Slight Coloration Differences
First, although all the photographs made during the sightings show very light-colored animals, the orca seen in Alaska appears to be just slightly darker than Iceberg. Such differences in coloration suggest that these were two distinct animals that were independently sighted in the northern Pacific.
Sightings Far Apart
Second, the sightings were very far apart. The Alaskan orca was seen near the central Aleutian Islands, a long string of islands that extends westward from the mainland of Alaska. Iceberg was seen near the Commander Islands, off the coast of Russia. More than 1,500 kilometers separate the two locations. Typically, orcas tend to stay near the mainland coast and not travel such long distances.
Age Estimates
Third, when scientists saw the Alaskan white orca in 2000, they estimated that it was around twenty years old, based on the size of its dorsal (back) fin. When researchers saw Iceberg, their estimate of its age, based on the fin size, was also around twenty years but that was in 2010, when the Alaskan orca would have been thirty! The estimates again suggest quite strongly that these are two different individuals.
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