1. There is a natural tendency for any relationship based on voluntary affection to come apart, but marriage provides the glue needed to keep a couple together by providing ties of family, in conjunction with the obligations of parents to children.
    任何建立在自发爱恋基础上的关系都会趋于自然终止，但婚姻建立起家庭纽带，以及父母与子女间的责任义务，这就提供了将夫妇联结在一起的粘合剂。

2. No doubt about it, solitude is improved by being voluntary.
    毫无疑问，如果自愿独处，则感觉要好得多。

3. She was a voluntary helper.
    她是自愿帮忙的。

4. It makes perfect sense to say that adult persons have a right not to be cloned without their voluntary, informed consent.
    未经通知并征得本人同意，成年人有权不被克隆，这是完全合理的。