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
答案选E，但是E的谓语单复数有没有问题啊？我选了B作者: yongjiew 时间: 2011-12-12 06:44
B 选项 没有谓语动词了~E选项 是倒装 看后面的 主语 应该是~the rate at which trees grow
