GRE Reading Comprehension: OG/PP2-GRE阅读OG/PP2 - SP16XGGJZB615609P

It can be inferred from the passage that Chinese observations of the Sun during the late seventeenth and early eighteenth centuries A. are ambiguous because most sunspots cannot be seen with the naked eye B. probably were made under the same weather conditions as those made in Europe C. are more reliable than European observations made during this period D. record some sunspot activity during this period E. have been employed by scientists seeking to argue that a change in solar activity occurred during this period