gre考试真题：90年10月阅读真题解析(A)
下面这篇是1990年10月gre考试阅读真题SECTION A部分。复习gre考试阅读的时候，gre考生应该以往年的真题为复习材料，从真题中总结阅读规律和特点才是制胜法宝。 It has been known for many decades that the appearance of sunspots is roughly periodic, with an average cycle of eleven years. Moreover, the incidence of solar flares and the flux of solar cosmic rays, ultraviolet radiation, and x-radiation all vary directly with the sunspot cycle (sunspot cycle: 日斑循环, 太阳黑点循环). But after more than a century of investigation, the relation of these and other phenomena, known collectively as the solar-activity cycle, to terre... [ 查看全文 ]gre考试真题：90年10月阅读真题解析(A)的相关文章
