38. ---I can’t find Mr. Zhang. Where did you meet him this afternoon?

---It was in the classroom _______ he taught.

A．that

B．which

C．where

D．the place

在人类社会由母系氏族公社向父系氏族公社过渡时，下列哪些因素起到了促进作用

①农业和畜牧业的发展②手工业的进步③以交换为目的的商品生产的出现④私有制的出现[ ]

A．①②③④

B．①②③

C．①②④

D．②③④