人际网由具有共同兴趣或爱好的人组成的非正式体系。人们互相帮助、互相交换信息或工作联系的进展 An informal system whereby persons having common interests or concerns assist each other, as in the exchange of information or the development of professional contacts.
该体系的永恒性不受任何事物的影响。 Nothing threatens the permanence of the system.
这两种体系只是在表面上有某种相似之处，其实根本不同。 There is only a formal resemblance between the two systems; they are in fact radically different.
英国於1971年改行十进制货币体系。 Britain converted to a decimal currency system in 1971.
