Mikrotik OS Bridge

Hi,
If I put two interfaces in a bridge and both are 1 gbps. Is the bridge then a 2 gig interface?

What happens if one interface in a bridge is 1 gbps and the other one is 100 mbps? Thus for example you plug a Netbox (1gbps port) in on eth2 and a UBNT rocket M5(eth port 100mbps) on eth3
and both ether2 and 3 in a bridge. wha tspeed is the bridge?

Thanks

Bridge does not Aggregate speed of ports, because is not an LAG! It just make a Virtual Switch!

thanks ingdaka