[讨论]难道是prep的疏漏？

这是prep得135题，答案A的问题是it是形式主语，那it指示是什么，为什么没有that？

At one time, the majestic American chestnut was so prevalent that it was said a squirrel could jump
from tree to tree without once touching the ground between New York State and Georgia.
(A) so prevalent that it was said a squirrel could
(B) so prevalent that a squirrel was said that it could
(C) so prevalent for a squirrel to be said to be able to
(D) prevalent enough that it was said a squirrel could
(E) prevalent enough for a squirrel to be said to be able to

(A) 正确，that后跟从句表示结果；it was said…中的it是形式主语。
(B) a squirrel was said that…被动语态的表达不如主动更明确。
(C) to be said to被动语态的表达不如主动更明确；so… to be的搭配错误。
(D) enough that搭配错误。
(E) enough to do所表达的含义与原句的so that不同；to be said to被动语态的表达不如主动更明确。

said后面是个主语从句  it指代整个从句

可搜索这一题的讨论，以前讨论过很多，有人说，当用say时，that可省略

 a squirrel could jump
from tree to tree without once touching the ground between New York State and Georgia.

是整个it的指代对象，不需要that