how much does it come to 请问这句子中,to 起到什么作用?在句中是什么成分?可以省略不要吗?

how much does it come to 请问这句子中,to 起到什么作用?在句中是什么成分?可以省略不要吗? How much does it cost? 中的"does"中这句中是起到什么作用?表示什么意思 请问句中的with是什么成分,起到什么作用? 英语语法How long does it take you to get to school? 此句中“it”是什么用法 My friends never come to visit me.中的never在句子中充当什么成分? 请问这是什么电路,有什么作用,三极管在电路中起到什么作用? 破折号在句子中起到什么作用? 关联词在句子中起到什么作用 i have much homework to do 中为什么可以省略后面的it how long does it take you to get from home to school?句中to ge introduce someone to another .请问to another 在句中是什么成分? How much is it going to cost和how much does it cost有什么区别?