Create wings for ground effect vehicle

My subject is to create the displayed feature for a vehicle. I already know how to do the airfoils

first question is. How do i get the airfoil to be filled and not to be hollow?

Second question is, how do i get the connection of these two airfoils?

It should look something like this:

Basically i only know how to create the two airfoils at the bottom. However i do not know how to create the horizontal and vertical "connectors"

Note that we just started using NX, so im a complete beginner. 

Any help is appreciated