作业帮The research requires more money than has been put in.这里为甚麽要用"has been put in"?
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The research requires more money than has been put in.这里为甚麽要用"has been put in"?
The research requires more money than has been put in.
这里为甚麽要用"has been put in"?
The research requires more money than has been put in.这里为甚麽要用"has been put in"?
首先是MONEY肯定是被投入的.
再有就是过去已经完成的动作了~!
助动词have的用法
1）have+been +过去分词,构成完成式被动语态,例如：
English has been taught in China for many years.(中国教英语已经多年.)
2)现在完成进行时构成：have / has been + 现在分词
用法:)下面详细举例：
用于表示动作从过去某一时间开始一直延续到现在或离现在不远的时间,动作是否继续下去,则需视起来而
定.如：
How long has it been raining?雨下多久了?
She has been sitting there for more than 2 hours.他已经在那坐了两个多小时了.
We’ve been seeing quite a lot of each other recently.最近我们常常见面.
He has been telephoning me several times in two days.这两天他打了好几次电话给我.
注意：使用现在完成进行时还有以下一些情况：
一般现在时 主要由动词原形表示,但第三人称单数后要加词尾s,另外be和have有特殊的人称形式
例：it all depends
he coves sports
i know it
现在进行时 由助动词be的人称形式加现在分词构成
例：i am working
一般将来时 由助动词shall will加动词原形构成
例：i shall go
you will go
一般过去时 由动词的过去式表示
例：i was glad to get your letter
现在完成时 由have的人称形式加过去分词构成
例：i have read it
he has read it
过去进行时 由be的过去式和现在分词构成,主要表示过去某个时刻正在进行的动作
例：the wind was no longer blowing．
过去完成时 由had加过去分词构成,主要表示过去某时前业已发生的动作或情况
例：they showed us the new machine tools they had turned out
一般过去将来时 由should would加动词原形构成,表示从过去某时看来将要发生的事情
例：he was sixty－eight,in two years he would be seventy
现在完成进行时 有have（has）been 加现在分词构成
例：how long has it been raining?
过去完成进行时 由had been加现在分词够成
例 ：it had been raining for two days the fields were all under water．
has been put in是现在完成时的被动语态。
has been put in 表示已经投入进去了的金额，而且这个金额是被投进去的，所以要用has been put in
这是过去完成时，has been put it是个被动时态 意思是已经被投入的。
有一个“than”在句中，说明存在一个比较关系，这类句子要求比较对象前后一致，而该题是将“require”和“have”比较所以