— Did Tom come back a little earlier last night?

— Yes, it was not yet twelve o'clock _______ he arrived home.

[      ]

A. when

B. that

C. why

D. which

刘公岛甲午战争博物馆的镇馆之宝是济远舰（）。

A、前双主炮

B、海水淡化蒸汽发生罐

C、吊艇架

D、船首