listEning 6 "historyClAss"
{$mEDiAurl}
whAt DoEs thE proFEssor imply ABout ConstruCtion mAtEriAls For EArly homEs
A、sEttlErs usED thE mAtEriAls From thE nAturAl EnvironmEnt.
B、not mAny oF thE mAtEriAls From thAt ErA hAvE survivED、
C、most oF thE suppliEs hAD to BE shippED in By rAilroAD、
D、wAgons AnD tEnts wErE usED in ConstruCting homEs.