句中的 presitge 有拼写错误,应该是 prestige
It's clear ‘it’作形式主语+系表结构,形容词 clear 作表语,词义:明显的
from the crowd's reaction 介词短语作状语表原因
that she has great prestige 由 that 引导的主语从句(后置了)
这个句子应该是这样的:
It's clear from the crowd's reaction that she has great prestige. 可以变形为:
That she has great prestige is clear from the crowd's reaction.
注:这是典型的主语从句后置的例子。