P3 Martian landscape大致内容：火星地表今年的变化给科学家带来很大的困惑。以前一个叫 G 的科学家提出地球有气候变化，比如冰川期，所以火星历史上因该也有，当时没有人能想到这点。现在科学家 M 对火星上半岛的研究：一些原先因为气候变化而形成的，由冰和灰尘构成的半岛在缩小成小岛，甚至消失。 继续说通过研究这些消失知道变化是由一些外部的能量M引起的，速度很快，估计 100 年内火星冰盖会完全融化。这也揭示了，火星冰盖含有的是二氧化碳，而不是冰。火星的风也没有以前的大，而且现在的火星气候现象无法解释火星的地表状况。题目：是非无判断，摘要。背景阅读：Data gathered by NASA’s Mars Global Surveyor spacecraft suggest that the martian climate may have changed significantly in the past, and may be changing quickly even now.According to two papers published in theDeC、7,2001, issue of Science, these changes many happen over a much shorter time scale than scientists previously thought. Images taken by the spacecraft’s camera system over a the course of a full martian year showed that pits in the planet’s perennial southern polar ice cap are growing dramatically. The only material that might have sublimated into gas so quickly was carbon dioxide ice, which was enlarging the pits by measurable amounts. The images confirmed a decades-old suspicion among researchers that the planet’s surface ice was made of solid carbon dioxide instead of frozen water. "This is prima facie evidence of climate change," says Michael Malin, of Malin Space Science Systems in SanDiego, who, along with colleagues MichaelCapliger and ScottDavis, is pricipal investigator for the Global Surveyor’s camera system."The measurements have rather profound implications, and bring into question a number of our views about the short-term stability of the martian climate"