中文: abbr. below threshold change 阈值下的变化; 临界值下的变化; beryllium thrust chamber 铍推力室; bus tie control 汇流排线控制
中文: abbr. better than expected 比预期的要好; breveté (French=patent) (法语)专利; battery terminal equipment 炮组端点设备; blunt trailing edge 钝后缘
中文: abbr. ball-tooth gear 球齿齿轮; beacon trigger generator 信标触发脉冲发生器; burst transmission group 脉冲串传输组; battery timing group 电池定时组