The first thing you need to do is (to) change your diet.这个句子为什么要加括号中的to?这个句子中还有什么句型或短语吗?请扣题详细讲解!

the first thing you are the first thing on my mind love You're the first thing I thought of every morning,the last thing that stays on my mind every night What'sthe first thing you think about when you wake up in the morning in the mornig when i rise you are the first thing on my mind. dont know the first thing about...另外 the last place you want to go When you arrive at school,the first thing is to greet the teacher为什么不是greeting When you arrive at school,the first thing is to greet the teacher为什么不是greeting The first thing( )you must do is to make a full plan. You are the first thing on my mind 谁帮我翻译下? 请翻译：You are the first and last thing on my mind!（日常口语） You're the first and last thing on my mind 帮我翻译下哦! l think the first thing you need to know about is her family. I have never forget the first thing ____ you taught me 用the first thing is造句 the whole thing first 怎么翻 first thing What's the first thing you'd do if you were going to build a house?它是虚拟语气吗?