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 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 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's for sb.和 It's of sb.的用法说一下这两个的用法和区别 it's 和it is的区别和用法?请问什么时候必须用it's ,什么时候必须用it is? 请问It和that的区别用法最好有举例 got it 和 get it 的用法 请问it's high time 的用法 it's和it的区别和用法it's和it有什么区别 请问so does it和so it does it各是什么用法? it,is,It's,its之间的用法和区别 it,is,It's,its之间的用法和区别 as it were和as it was的用法区别 one和it用法的区别 代词it和that的用法 关于of和for的用法请问下面这个句子“这是一辆长沙代理商的库存”,是这样翻译对“it is an inventort of Changsha dealer”,还是 “it is an inventory for Changsha dealer” 这样对? (1/2)请问一下worthy 和worthwhile 的用法句子They did not find it __to prepare for Here you are和Here it si用法区别!两个都是“给你”的意思,他们的用法区别! It的用法