"It looks as if从句"和“It's 3 years since 从句”两句的的IT的含义和用法?请问下面这两个IT的含义和用法?1 It's 3 years since 从句；2 It look as if从句.如果是形式主语,也不对啊,SINCE和AS IF引导的都不是

关于as if引导表语从句和宾语从句.语法书中说下面这句话中as if引导的是表语从句：It looks as if it is going to rain.那么为什么有的语法书中说下面的句子中as if 引导的是壮语从句：She looks as if sh It looks as if从句和“It's 3 years since 从句”两句的的IT的含义和用法?请问下面这两个IT的含义和用法?1 It's 3 years since 从句；2 It look as if从句.如果是形式主语,也不对啊,SINCE和AS IF引导的都不是 it looks as if she 's It's looks as if it is going to snow和It seems that ····分别是什么从句?为什么?都有引导词.都有连系动词.怎么区别这两个是什么从句 as if it looks as if is going to rain.看上去天要下雨了.在这句里面as if as if在表语从句中只跟在look it looks as if it is going to rain looks as if he was dead 和he looks as if he is dead的区别. It looks as if cold.这句话对吗? “似乎要下雨了”应该用 it seems as if 还是it looks as if 为什么it seems as if=it looked as if而不是looks为什么是looked不是looks He looks as if he were hungry是表语从句还是方式状语从句?如何判断? 句型It seems/looks like...1.It seems/looks like...主语IT能换成其他的名词或代词吗?LIKE是介词还是连词?还是介、连词都可以?2.It seems/looks as if...IT代替AS IF引导的表语从句吗?IT能换成其他的名词或代词 It looks as if/as though it’s going to rain这句话是什么意思? 英语翻译It looks as if it's going yo rain.刚刚打错了It looks as if it's going to rain. as^though于as^if引导从句表假设时都连过去时,但表事实时用那个连接?it^looks^as〔填那个〕^is^going^to^rain. 请问下面这两个IT的含义和用法?1 It's 3 years since 从句；2 It look as if从句.如果是形式主语,也不对啊,SINCE和AS IF引导的都不是主语从句, It looks ___it is going to rain.A as if B like C as D that It seems as if 属于什么从句类型?