All of the guests ________ by 9 o'clock, but the host ________ until 15 minutes later.[ ]

A. arrived; didn't show up    

B. had arrived; didn't show up

C. arrived; hadn't turned up    

D. had arrived; hadn't turned up

一家日本企业在征得清政府同意后，在重庆开设一工厂，这是在

A．鸦片战争后

B．洋务运动中

C．第二次鸦片战争中

D．甲午中日战争后