to 后面可接句子吗？

xixiokok

/ W+ ^' `  p5 L) sIn 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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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

没有接句子
# r1 T7 P, s+ Z- t! Eit is necessary to have done sth.
4 X, N) c$ T# E( |/ k接了个完成时的动宾结构
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; p+ K, l6 [6 V6 t/ Z) p你可以对比一下下面两句的含义
; s. P3 w+ C% S$ k* Sit's necessary to acquire this.
: z, L* p# ?7 G4 P有必要（现在或以后）去获取这个
it'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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