what is the company's principal field of activity如何翻译

have as one's principal field of study.
作为一个人主要的学习对象.
Apart from ensuring that the Fund meets its statutory roles,the HKMA's principal day-to-day activity is the management of the Fund's assets.
除了确保外汇基金履行本身的法定职责外,金管局的日常工作,主要是积极管理外汇基金的资产.
Apart from ensuring that the fund meets its statutory roles,the HKMA's principal activity on a day-to-day basis is the active management of the fund's assets.
除了确保外汇基金履行法定职责外,金管局的日常工作主要是积极管理外汇基金的资产.
This fall within the company's range of activity.
这属于公司多种业务活动之一.
What were the principal conclusions of Hitchcock's survey?
希治阁的调查有什么主要的结论呢?