ttgwd 10-26 gwd 10-37

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.

1. On Earth, among the surest indications of sunspot cycles are believed to be the rate that trees grow

2. On Earth, among the surest indications of sunspot cycles are, it is believed, the rate of tree growth

3. On Earth, the rate at which trees grow is believed to be among the surest indications of sunspot cycles

4. Among the surest indications on Earth of sunspot cycles, believed to be the tree growth rate

5. Among the surest indications on Earth of sunspot cycles is believed to be the rate at which trees grow

我用xy和tt的编号都搜不到。。虽然以前看到过 。。 答案是c

A，B 倒装句， 可知道谓语是错的

D 明显不叫句子了

D,E中的on earth 夹在那么尴尬的一个位置上

我觉得， C是最好的 ，没什么错