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.  

, q3 t. l- m$ u% e这句话里，necessary to 后面为什么可以接 have acquired a ...句子？

江南一屁

没有接句子
it is necessary to have done sth.
0 `8 L9 }& B8 W/ A# ^2 n% S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.
+ w) ?$ N" |* Z8 l: \+ O有必要（现在或以后）去获取这个
it's necessary to have acquired this.
6 l/ ^# u& U* e4 }7 B1 \; R有必要目前已经获取了这个（具有这个是有必要的）
+ b8 a* w! s& O# m  D+ v
' W8 k5 I% G9 z& o; [