to 后面可接句子吗？

xixiokok

: \2 g8 m$ r  C. n5 fIn 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 O7 j; J3 I2 B$ x4 r这句话里，necessary to 后面为什么可以接 have acquired a ...句子？

江南一屁

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7 H# O, o) @; a* A没有接句子
2 i5 A  E* b% u7 T( ]it is necessary to have done sth.
' h' ~* x/ G9 c0 q接了个完成时的动宾结构

你可以对比一下下面两句的含义
it's necessary to acquire this.
: ~: W2 S# R9 {% c/ F7 h* K有必要（现在或以后）去获取这个
  W/ Z+ t3 x. K5 sit's necessary to have acquired this.
6 ]' v2 [* u  n& m  J' q' x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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+ D* ~$ z4 H3 c0 B