“What place is it?” “Haven’t you found out we _____ back where we ______?”

A．were, had been

B．have been, are

C．are, were

D．are, had been

沥青混合料马歇尔稳定度试验，标准马歇尔试件应在60℃±1℃的恒温水中恒温30min～40min。