It was after what seemed like a century ________ we were allowed to go home.

A．when

B．which

C．as

D．that

周某在乘坐飞机时，由于一点小事与邻座乘客发生争吵，并大打出手，殴斗中，周某用铝质送餐车将舷窗砸坏，致使机舱内气压下降，乘客出现骚乱现象。周某的行为应认定为(　)。

A．尚未构成犯罪

B．已构成破坏交通工具罪

C．已构成劫持航空器罪

D．已构成暴力危及飞行安全罪