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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9 L/ M; N  M4 [( [这句话里，necessary to 后面为什么可以接 have acquired a ...句子？

江南一屁

- o; v! G  C+ W7 T3 e& ]4 |没有接句子
it is necessary to have done sth.
9 B- S) d: }0 x1 w6 t接了个完成时的动宾结构
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! }2 @5 [# n; ?9 z* W7 P. u- y: j你可以对比一下下面两句的含义
7 ?$ T' C6 s1 w- Y* jit's necessary to acquire this.
% d9 [7 d9 K6 u! Q( ~1 i1 ]有必要（现在或以后）去获取这个
% i; M3 s* [. P- h4 A/ C! b6 Z7 \+ Wit's necessary to have acquired this.
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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