Look!A new road ---------(build) in the town.

Look! A new road is being built in the town.瞧,城里正在建一条路.
Look!表示：你看!那就是眼前的事情,一般用于现在进行时.
当然,你要是强调眼前已经建成了一条路,那就应该这样说：
Look! The new road has been built in the town.（瞧,城里那条新路已经建成了）