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题库 / Prep2007E1-SC-139
On Earth, among the surest indications of sunspot cycles are believed to be the rate that trees grow, as seen in the rings visible in the cross sections of their trunks.
On Earth, among the surest indications of sunspot cycles are believed to be the rate that trees grow
On Earth, among the surest indications of sunspot cycles are, it is believed, the rate of tree growth
On Earth, the rate at which trees grow is believed to be among the surest indications of sunspot cycles
Among the surest indications on Earth of sunspot cycles, believed to be the tree growth rate
Among the surest indications on Earth of sunspot cycles is believed to be the rate at which trees grow
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as seen过去分词作伴随状语，逻辑主语是主句主语the rate at which trees grow，这点C/E都是合理的
C，on earth作主句状语，修饰谓语动词is believed，意为在地球上，树木的生长速率被认为是最可靠的迹象之一（那么在月球上就不这么认为了？）；E，on earth作indications的定语，是地球上最可靠的指标之一，ok
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