1. Stars like our sun fuse hydrogen in their cores into helium. 太阳一类的恒星在其核心将氢聚变成氦。
2. Analyses of these cores and samples provide a different solution to the problem. 对这些岩心和样品的分析为这个问题提供了一个不同的解决方案。
3. Findings from the upper sections of the cores have confirmed what scientists already knew—climate during the last ice age fluctuated rapidly. 来自岩心上部的发现证实了科学家们已经知道的情况：最后一个冰河时代的气候变化非常快。
4. But, unlike the cores of the inner planets, the Moon's core contains little or no iron, while the typical planet-forming materials were quite rich in iron. 但是，与内行星的核心不同，月球的核心几乎不含铁，而典型的行星形成物质则富含铁。
5. For the time before records began, we have only "proxy records" reconstructed largely from tree rings and ice cores, supplemented by a few incomplete written accounts. 在开始有记录之前，我们只有主要根据年轮和冰芯重建的“代理记录”，还有一些不完整的书面记录作为补充。
