英语考试中遇到he found

英语考试中遇到he found ___ important...总是错 请问sb.found+ it / that / it's用法?
found后面加it that it's后面跟什么样的句型

find 基本用法有：
1、find v. 找到,句型为find + n. 如：I can't find my key.
2、find v. 发现,觉得.基本句型两种：
A. find it + adj. + for sb. to do sth. 如：I find it difficut for me to read English novels.
B. find + that 从句.如：I find that he is really cute.
至于find it's . 实际上是find + that 从句的句式.只是find 之后的宾语从句引导词that省略了而已.从句中运用了it's + adj. + for sb. to do sth.的句型.比如上句I find it difficult to read English novels. 可以改写为：I find (that) it's difficult for me to read English novels.
关于从句引导词省略问题,采纳后可以继续追问.