A-A+
Based on the research Niswander cautions that
问题详情
Based on the research, Niswander cautions that
A．the practice of recommending folic acid for the pregnant needs reconsidering.
B．it is still controversial whether folic acid is good for human fetuses.
C．it is too early to judge the effects of folic acid.
D．pregnant mothers cannot take an overdose of folic acid.请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：C
解析：推理判断题。第五段Still一句发生转折，虽然Niswander怀疑高含量的叶酸在一些情况下对人有害，但是她仍强调，在重新考虑推荐准妈妈们服用多少叶酸之前需要收集更多的数据(即仍需做更多的研究工作)。据此判断，Niswander认为该项研究还不足以说明叶酸对人的影响，[C]“评估叶酸的影响为时尚早”正确。[A]与[B]与文意相反。[D]文中未提及。
