vocational work;professional work; business;
钻研业务 diligently study one's profession
恢复正常业务 resume normal business
业务范围 scope of business
业务能力 professional ability (or proficiency)
业务水平 professional skill;vocational level;
业务协定 business agreement;
业务学习 vocational study
业务知识 professional knowledge
业务尖子 top-notch professional
个人认为:
口语中说到某项业务(服务)时可以用service