quEstions 17～20 ArE BAsED on thE Following tAlk. you now hAvE 20 sEConDs to rEAD quEstions 17～20.
whAt hAppEnED to thE ChilD in FrEDEriCk ⅱ’s ExpErimEntA．thE ChilD’s BrAin wAs DAmAgED、
B．thE ChilD DiED、
C．thE ChilD kEpt silEnt.
D．thE ChilD hEArD no mothEr tonguE.