Vacuum hose question

[rhag1128]

I am coming down the home stretch with my engine replacement on my 99 XC70.....
There is a hard plastic duct that runs underneath the intake manifold, one end connects to the throttle body. This duct has the air temp sensor in it and next to that a long white nipple for vacuum hose. Does anyone know where this hose comes from-goes to?

Also, this duct where it connects to the TB does not seem to be large enough in diameter to fit over and put a clamp on, any ideas on this either?

Thanks