First of all,I found ____very difficult to understand what the forigner said.A.it is B.its C.it D.that标准答案是：C二楼的，能问下为什么选C吗？

First of all,I found ____very difficult to understand what the forigner said.A.it is B.its C.it D.that标准答案是：C二楼的，能问下为什么选C吗？
First of all,I found ____very difficult to understand what the forigner said.
A.it is B.its C.it D.that
标准答案是：C
二楼的，能问下为什么选C吗？

First of all,I found ____very difficult to understand what the forigner said.A.it is B.its C.it D.that标准答案是：C二楼的，能问下为什么选C吗？
c(find it+adj.to do sth.是发现做某事很...的意思)