同学你好，该知识点来自沪江网校《【Uni智能】雅思名师带练7分冲刺营【9月签约班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学你好，
“be of+ 抽象名词（ value,importance,use,help,interest 等）”相当于“be + 该抽象名词相对应的形容词”.其中 of 表示“具备；具有”,of 不可以省略.例如：
They are of great help / very helpful to learners of English.
　　他们对英语学习者来说是很有帮助的.
The press conference seems of great importance / very important.
这个新闻发布会看来很重要.
Of particular importance among these were meetings that discussed the potential effects of global warming这句话相当于 meetings（ that discussed the potential effects of global warming定语从句，先不管） were of particular importance （among these限定范围，这些会议中讨论全球变暖的潜在影响的会议非常重要） 这里of particular importance= particularly important特别地重要
然后为了突出重要性将of importance提前，变成了原文中的句子
Of particular importance /among these /were /meetings （that discussed the potential effects of global warming）

希望对你有帮助哦O(∩_∩)O