A:Answer The motherboard does have two PCIE x16 slots, but there are a couple of caveats.
One of the x16 slots only has 4 data lanes, so it's physically an x16, but electrically it's an x4, and as such it cannot transfer data as fast as a full 16-lane slot.
Another caveat is power. Is there enough power for a second power-hungry GPU? And is there a power connector for the second GPU? The power supply is supposed to be 600W, so I'm guessing you're probably OK (I have not dug around looking for a second connector but I assume that it's in there somewhere.) FWIW, I believe I've seen assertions from the manufacturer that it can handle these cards.
If you need a bigger power supply, that could be a problem, since the power supply is an unusual form factor. Probably most replacement power supplies will not physically fit in this chassis.