ACCorDing to thE Author, thE grEAtEst mistAkE oF our ForEFAthErs wAs thAt______.
A．thEy hAD no iDEA ABout sCiEntiFiC ForEstry
B．thEy hAD littlE or no sEnsE oF EnvironmEntAl protECtion
C．thEy wErE not AwArE oF thE signiFiCAnCE oF nAturE stuDy
D．thEy hAD no iDEA oF how to mAkE gooD usE oF rAw mAtEriAls