prep1-139 还是不懂

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.

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

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

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

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

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

E这句话是什么意思啊？ as seen in the rings...是个什么从句？

这题的主语是the rate,结构是Among...is believed to be,是个倒装句。

我来试试翻译一下：目前世界上对于太阳黑点循环的观点中，把握性最大的是根据对树干横截面年轮圈的观察来判断树木增长的速度。

艾！还是不懂

on earth放在句首也可以，不过别的选项都有错误，所以e是答案。具体参考楼上。on earth的位置不是本题的语法点。

E的结构恢复过来应该是这样子的：

the rate at which trees grow is believed to be among the surest indications on earth of sunspot cycles, as.........

indication是‘迹象，指示’；

on earth是修饰这个indication的，应该理解为on earth的indication；

而AC，on earth就是修饰...is believed...的，好像只有on earth才被believed一样；

B,on earth是修饰...rate are among...的，好像是只有on earth这个rate才among一样；

所以ABC的on earth也是一个重要的考点；