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.  

这句话里，necessary to 后面为什么可以接 have acquired a ...句子？
$ [! K% L, B, e" x9 v

江南一屁

没有接句子
it is necessary to have done sth.
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
$ m9 I7 a6 x* }3 X7 ~  L* c) ait's necessary to acquire this.
$ G8 q9 l4 R. R有必要（现在或以后）去获取这个
# e, l4 D1 T! D$ R( S+ ^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）
7 \) m! B. P2 p, Q! U$ p