thErE ArE ADvAntAgEs AnD DisADvAntAgEs oF onlinE DistAnCE lEArning. onE ADvAntAgE is ______.
A．it is EAsy to Do
B．it is ChEApEr thAn FACE-to-FACE lEArning
C．it is ConvEniEnt
D．it is sAtisFying