eg. Delivery is free of charge.
免费送货。
The department store delivers free of charge.
eg. 这家百货商店免费送货。
eg. The conversation is encrypted and, while in the network, free of charge.
谈话内容经过加密处理，而且在网内是免费的。
2. demonstrate vt. 证明；展示；论证
vi. 示威
eg. How can I demonstrate to you that my story is true?
我怎么才能向你证明我的话是真的呢?
eg. An example will demonstrate how these objects work together.
示例将验证这些对象如何一起工作。
3. It helped me out a lot. 收获不少。
