一 什么是名词从句
名词或名词短语主要充当四种句子成分：主语、宾语、表语和同位语，于是便构成了四种从句：主语从句、宾语从句、表语从句、同位语从句。
- 主语从句
eg：What I am reading:主语
What I am reading is interesting - 宾语从句
eg:the life on other planets:宾语
No one knows exactly the life on other planets：没人能够确切的知道外星人 - 表语从句
eg:what I like most among all subjects
English is what I like most among all subjects:英语是所有科目中我最喜欢的一门 - 同位语从句
eg:that love,not time heals all wounds
I love the saying that love , not time heals all wounds .我喜欢这句话：是爱而不是时间能够治愈一切创伤
二 简单句与主语从句
1. It is + 过去分词 + that从句
- It's reported that...（据报道）
- It's believed that...（人们相信）
- It is generally thought that...（人们普遍认为）
- It has been found that...（现已发现）
- It should be noted that...（应该注意）
- It must be pointed out that...（必须指出）
2. It is + 形容词 + that从句
- It is clear that...（显然）
- It is likely that...（很可能）
- It is certain that...（可以相信）
- It is fortunate that...（幸运的是）
- It is possible that...（很可能）
- It is natural that...（很自然）
- It is strange that...（奇怪的是）
- It is necessary that...（有必要）
3. It is + 名词短语 + that从句
- It is a pity that...（可惜的是）
- It is good news that...（真是太好了）
- It is no wonder that...（难怪）
- It is an honor that...（真荣幸）
- It is my belief that...（我相信）
- It is fact that...（事实是）
- It is a good thing that...（真是件好事）
- It is a shame that...(遗憾的是）
- It is common knowledge that...（...是常识）
- It is a miracle that...（...是奇迹）
