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.
GWD-10-Q20 In the mid-1970’s, 【since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that reduced】automobile emissions.
A. since birds were overcome by pollution, and routinely falling from the sky above Los Angeles freeways, this prompted officials in California to devise a plan that reduced B. same as A C. birds had been overcome by pollution and routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan that reduced D. birds overcome by pollution routinely fell from the sky above Los Angeles freeways, prompting officials in California to devise a plan to reduce E. birds overcome by pollution and routinely falling from the sky above Los Angeles freeways, were prompting officials in California to devise a plan to reduce
D
GWD-10-Q37:GWD-11-26 【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E 麻烦大牛们解析一下。。。。THX