7.  Variables such as individual and corporate behavior make nearly impossible for economists to forecast economic trends with precision.
  • 1、
【正确答案】 1、B。it形式宾语用法。根据句子结构，主语是variables，空格中需要填入谓语成分，空格后面的nearly impossible充当补语成分，for economists...短语充当真正的宾语，谓语动词后面必须由形式宾语it补充完整。    
【答案解析】