非谓语动词

 There are mud and water all over, making it hard for people to go through 这里的it是不是指的就是 for people to go through，若是，那样这个句子能否改为there are mud and water all over, making for people to go through hard。这里的不定式是干什么成分呢。

期望老师解答一下，谢谢

There are mud and water all over, making it hard for people to go through.

make sth hard 为复合宾语结构，sth为宾语，形容词hard为宾补。当宾语为不定式或that从句时，需要用虚指it作形式宾语，真的宾语（不定式或that从句）外置（即坐落于句末）。
非谓语动词作状语，其逻辑主语被默觉得句子的主语。 Seen from the highest building, the cars and people are small. 句子主语与see是被动关系，所以用过去分词短语作状语，维持主动与被动的一致。