第五条 民事主体从事民事活动，应当遵循自愿原则，按照自己的意思设立、变更、终止民事法律关系。

思路：

【主句】民事主体【从句1，表示时间】从事民事活动，应当遵循自愿原则，【从句2，解释说明】按照自己的意思设立、变更、终止民事法律关系。

译文：Article 5 Civil persons when conducting civil activities shall act in accordance with the principal of voluntariness, creating, modifying, and terminating civil relationships according to their own will.

类似句型的条文如下：

第六条 民事主体从事民事活动，应当遵循公平原则，合理确定各方的权利和义务。

译文：Article 6 Civil persons when conducting civil activities shall act in accordance with the principle of fairness, properly clarifying the rights and obligations of the parties.

第七条 民事主体从事民事活动，应当遵循诚信原则，秉持诚实，恪守承诺。

译文：Article 7 Civil persons when conducting civil activities shall act in accordance with good faith, upholding honesty and honoring commitments.

Source: Civil Code of the People's Republic of China-General Part (translated by Lingyun Gao)