下列对秦朝短期而亡的主要原因的分析，最准确的是 [ ]

A．“焚书坑儒”

B．不讲礼义廉耻，所以人民叛离

C．因为秦统一了六国的货币、度量衡等

D．暴虐措施使人民不堪忍受

We ________ the difficulty together，but why didn't you tell me?

A．should face

B．might face

C．could have faced

D．must have faced