评文：The effective period of the Foreign enterprise Resident Representative Office Registration Certificate shall be the period of residence that has been approved, and if the period is exceeded, registration procedures shall be completed again. In cases where the approved period of residence is one year or more， registration procedures shall be completed once each year.

本语段中period是ー个中心词汇，它在本语段中连续出现了四次。它既不可以在有的句中省略，也不可以用其他的代词来替代。

4. 情态动词的高频率使用

经济法规的主要内容就是表现司法主体对司法客体行为的制约。它明确地要求司法客体“可以”“能够”“必须”做什么;反之要求 司法客体“不可以”“不能够不需要”做什么。因此,情态动词在经济法规文体中是高频率使用的词汇。

法规例句4：外国人员、华侨、港、澳、台人员的工资及其他正当收益，依法纳税后，可以汇出或携出。

译文：Salaries and other legal incomes by foreigners, overseas Chinese, residents of Taiwan，Hong Kong and Macao，after payment of related taxes, may be remitted or brought overseas.

法规例句5: 区内企业须经外汇局批准，在规定的浮动幅度内挂牌。

译文：In-area enterprises will have to have the approval of the local exchange control bureaus within the stipulated fluctuation scope.