Ab extends by 2mm and bc contracts by 2mm . AB伸长2mm，而BC缩短2mm。
Soldiers of bad character were branded bc . 对品质恶劣的军人烙BC型烙印。
Glass-making flourished as early as 1350 bc . 早在公元前一千三百五十年，玻璃制造业已十分发达。
The tube abc shown is cantilevered with ab and bc in a horizontal plan . 所示的管ABC是由位于同一水平面内的AB和BC组成的悬臂。
the vertical displacement =1mm is normal to the bars ab and bc and hence does not affect their length. 竖向位移1mm垂直于AB和BC，故不影响它们的长度。
The temple which the archaeologists explored was used as a place of worship from the fifteenth century bc . until roman times . 考古学家们所考察的这座古庙，从公元前十五世纪一直到罗马时代都被用作做礼拜的场所。
After all these concepts go back to 400 bc 毕竟那都是些公元前400年前的概念了。
The scene is laid in athens , in the third century bc 背景是纪元前3世纪的雅典。
Invaded the city of jerusalem right about 9880 bc , 于公元前980年侵略了耶路撒冷
The first olympic games took place in 776 bc 第一次奥运会于公元前776年举行,
