"(be)+of+名词"结构中的名词是抽象名词时,相当于其中名词所对应的形容词的意思,说明被修饰词具有某种特征或属性.常用的名词有use/importance/help/value/interest/quality/service/benefit/necessity等.
例如:
I don't want to hear what you are saying.It is of no interest to me.我不想听你说,我对此不感兴趣.
(of no interest=not interesting) Doing morning exercises will be of benefit to your health.做早操对你的健康有利.
Coal is of great importance to the development of industry.煤对工业发展是相当重要的.(of great importance=very important)
所以
It was of the very highest quality 它质量上乘/ 它具有上乘的质量.