1. 准备就绪 决定动手做 熟练(某事)：be on intimate terms with || 与关系密切 | be on it || 准备就绪 决定动手做 熟练(某事) | be on its course || (船)航向不变

2. [美口]准备就绪; 决定动手做; 熟练(某事)：be on at 不断地找岔[唠叨] | be on it [美口]准备就绪; 决定动手做; 熟练(某事) | be on to 清楚; 识透; 对某人找岔子; 与...联系[商谈]

3. 在做：Device:装置 | Be on it:在做 | Step off:抬脚