Question

moving magnetism
scientists from the geological survey of canada go hunting every few years. they dress in thick winter coats and warm gloves, tuck compasses in their pockets, and jump on airplanes that fly out over canadas arctic region. they look down on a vast and empty landscape with only a few tiny islands and shiny sea ice. what they hunt is always moving and cannot be seen with their eyes. these scientists are hunters of earths magnetic north pole.
in december 2003, earths north magnetic pole was located 600 kilometers from the northern canadian town of resolute bay. but it has not always been there and it will not stay. in 1831, explorer james ross found the pole for the first time. no one looked for it again for over 70 years because the weather conditions were so dangerous. rosss ship had been stuck in the arctic ice for four years! in 1904 when roald amundsen looked again and found the magnetic north pole, it had moved 50 kilometers.
sometimes, the earths magnetic north pole even trades places with the magnetic south pole. this strange event has been recorded in the magnetism of ancient rocks and happens about every 300,000 years. geologists cant predict when the poles will swap places again.
scientists have been recording the movement of the magnetic north pole across canada since james ross first found it. it was moving at an average speed of 10 kilometers a year until the end of the 1900s. then the speed increased to 40 kilometers per year. one day in the near future, the scientists from the geological survey of canada will have to do their hunting in siberia instead of canada.
4
which detail from the passage should be included in the summary?
a. in 1904, when roald amundsen looked again and found the magnetic north pole, it had n kilometers.
b. they look down on a vast and empty landscape with only a few tiny islands and shiny sea ice.
c. no one looked for it again for more than 70 years because the weather conditions were so dangerous.
d. scientists from the geological survey of canada go hunting every few years.
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Explanation:

The passage's main topic is about scientists (from the Geological Survey of Canada) hunting the moving magnetic north pole. Option D directly states the key subject - scientists from the Geological Survey of Canada and their action (go hunting every few years), which is central to the passage.

• Option A: Only mentions a specific year (1904) and a detail about the magnetic north pole's movement (had moved 50 kilometers) but doesn't capture the main subject (the scientists' activity).
• Option B: Describes the landscape they look down on. It's a minor detail in the passage, not the main idea.
• Option C: Talks about why no one looked for the pole for 70 years (weather conditions). It's a supporting detail, not the main point.

Answer:

D. Scientists from the Geological Survey of Canada go hunting every few years.