Over long periods of time, substances whose physical and chemical properties change with the ambient climate at the time can be deposited in a systematic way to provide a continuous record of changes in those properties overtime, sometimes for hundreds or thousands of years. Generally, the layering occurs on an annual basis, hence the observed changes in the records can be dated. Information on temperature, rainfall, and other aspects of the climate that can be inferred from the systematic changes in properties is usually referred to as proxy data. Proxy temperature records have been reconstructed from ice core drilled out of the central Greenland ice cap, calcite shells embedded in layered lake sediments in Western Europe, ocean floor sediment cores from the tropical Atlantic Ocean, ice cores from Peruvian glaciers, and ice cores from eastern Antarctica. While these records provide broadly consistent indications that temperature variations can occur on a global scale, there are nonetheless some intriguing differences, which suggest that the pattern of temperature variations in regional climates can also differ significantly from each other.
3.According to paragraph 3, scientists are able to reconstruct proxy temperature records by
- A.studying regional differences in temperature variations
- B.studying and dating changes in the properties of substances
- C.observing changes in present day climate conditions
- D.inferring past climate shifts from observations of current climatic changes
이 문제요, 저는 답을 a라고 해서 틀렸어요.....
답은 b인데요, ........아무래도 모르겠어요ㅠㅠㅠㅠㅠㅠㅠ
근거좀 알려주세요~