分析其句子成分?Until now scientists had very little clear evidence about the drug's role in preventing more serious effects of infection.“about drug's role”是不是介词短语作补语?“in preventing more serious effects of infection”是什么?effect在这里是什么意思？
问题描述：
分析其句子成分?
Until now scientists had very little clear evidence about the drug's role in preventing more serious effects of infection.
“about drug's role”是不是介词短语作补语?“in preventing more serious effects of infection”是什么?
effect在这里是什么意思？
答
about drug's role是介词短语
后面那个是 阻止更严重的感染反应
答
至到最近,科学家对于这种药物在阻止感染的严重后果（方面）的作用只掌握很少的明确证据.主语 scientists谓语 had 宾语 very little clear evidence about the drug's role 宾语补足语 in preventing more serious ef...