to 后面可接句子吗？

xixiokok

In order to design policies that aim to change commuting practices it is, however,necessary to have acquired a good understanding of the trips in question and their determinants.  
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# I7 c  l! ~( h& r这句话里，necessary to 后面为什么可以接 have acquired a ...句子？
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江南一屁

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没有接句子
it is necessary to have done sth.
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你可以对比一下下面两句的含义
* T* I4 @4 \5 Wit's necessary to acquire this.
有必要（现在或以后）去获取这个
2 s4 }* b$ u- o/ ]  ?- W$ n- lit's necessary to have acquired this.
1 P6 i, v/ b( I有必要目前已经获取了这个（具有这个是有必要的）

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