whAt CAn wE lEArn From thE First pArAgrAph ABout thE CritiCAl pErioD
A．it is A point At whiCh thE proCEss oF lEArning EnDs.
B．it is A phAsE whiCh is CruCiAl to thE ACquisition oF A CErtAin ABility.
C．it is A phAsE AFtEr whiCh wE Do not nEED to ACquirE A CErtAin ABility.
D．mAns AnD AnimAls hAvE A similAr CritiCAl pErioD For A CErtAin ABility.