ACCorDing to this pAssAgE, to BE A pArA-proFEssionAl onE ______.
A．usuAlly rECEivEs somE trAining For DoCtors' work
B．is trAinED ExtEnsivEly For A CErtAin pErioD oF timE
C．grADuAtEs From A mEDiCAl CollEgE or sChool
D．goEs ovEr thE BAsiC CoursEs within 18 months