boomn.繁荣；兴旺；激增；低沉声n.帆杠；吊杆；支臂；尾桁；水栅vi.急速增长；发出低沉声vt.使兴旺；促进booming kick踢吊球boom or bust经济繁荣和萧条的循环boom section喷杆组boom sprayer喷管式喷雾器boom derrick吊杆转臂起重机boom antenna桅杆塔式天线boom cylinder转臂油缸boom operator吊杆操作员boom - type悬臂式boom and bust经济萧条和经济繁?,经济萧条和经济繁荣的交替循环,经济繁荣与萧条的交替循环