单选题 It is evident that, in speculating about twisting effects, Nodland and Ralslon focused mainly on______.

A、 unconventional measurement instruments.
B、 assumptions and deductions.
C、 references to scientific literature.
D、 discrimination against basic doctrines.

【正确答案】 B

【答案解析】[精解] 本题考查推理判断。文章第五段结尾提到“But Nodland and Raison
wondered whether additional twisting effects might be at work．”，可见Nodland 和Raison 有关旋转效应的思索主要建立在假设和估计的基础之上：文章第四段开头也间接提到，其他理论学家也怀疑这种说法经不住严密推敲。