first可以省略the吗?first什么时候加the?什么时候不加the?

first可以省略the吗?first什么时候加the?什么时候不加the? it is the first time that 是状语从句还是定语从句,that可省略吗?It is the first time I have met him.中the first time 又不是充当宾语，why可以省略？ the first后面可以省略么This company was the first to produce portable radios in the world.the first后面什么都不接也可以么 The first lesson is very easy .第一课很简单.例句中的the可以省略吗?为什么? Is this hovercraft the one that made its first public flight in 1959?中的that可以省略吗,为什么 表语从句是否可省略thatThis is the first time that I have seen you.这句话是表语从句吗?这个that可以省略吗..还有什么时候that可以省略 什么时候不省略啊.. THAT什么时候可以省略The first thing that should be done is get the book这句话中的that 可以省略吗?为什么?哪错了?别管那些 说重点 到底能不能省略? Our room is on the first floor and yours is on the second.这句话后一个is 可以省略吗? My first impression of Mrs Li was that she was nervous and shythat 可以省略吗? ON the morning of March first.可以这样翻译吗?on the morning on march first The first day when we met / The day when we first met.这两种都可以吗? first they should work the cost out carefully.first可以单独用吗?和at first有什么区别 The first time that I went away from home without my parents was when I was ten.that 从句做什么成分?that 可以省略吗? the first The first 什么情况下可以省略that?the first thing i need to buy is a bed and cough 为什么可以省略that first and foremost 前面可以加the吗 twenty-first怎么发音?是念：twenty the first ；还是念：twenty first就可以?