From thE pAssAgE wE CAn DrAw thE ConClusion thAt long pErioDs oF slEEplEssnEss mAy proDuCE ______.
A．lAsting hArm to thE BrAin
B．A loss oF ChEErFulnEss ForEvEr
C．no pErmAnEnt DAmAgE
D．somE sErious AFtEr-EFFECts