最近大家都谈“核”色变，好像核辐射随时都有可能伴着风雨来到中国。其实，真正的状况并没有我们想象的那么危急。不过，为了配合大家谈“核”的热情，小编今天特地选了一个跟nuclear有关的词来讲讲。

A nuclear family is a family group consisting of a father and mother and their children, who share living quarters. This can be contrasted with an extended family. Nuclear families can have any number of children, own or adopted.

Nuclear family（核心家庭）指由一对夫妻及其子女组成，并且共同居住在同一屋檐下的家庭。与之相对的就是extended family（大家庭）。核心家庭中的子女，无论是亲生的还是收养的，在数量上并无限制。

The term nuclear is used in its general meaning referring to a central entity or "nucleus" around which others collect.

这里的nuclear用的是它本意，即事务或人围绕的“核心，中心”。

An extended family group is consisted of non-nuclear family members living together with nuclear family members. Often there could be many generations living under the same roof, depending on the circumstances.

Extended family（大家庭）则是由核心家庭成员及该家庭之外的成员组成的家庭，通常是几代人共同生活在一起。