importance是抽象名词。抽象名词属于不可数名词。
例句：
They attach great importance to the project.
他们高度重视这个项目。
相关介绍
Reducing levels of carbon dioxide in the atmosphere is of critical importance.
减少大气层中的二氧化碳含量极其重要。
His speech emphasized the importance of attracting industry to the town.
他的发言强调了吸引工业到城镇的重要性。
He was very aware of his own importance.
他十分清楚自己的重要地位。
This issue was of such importance that we could not afford to ignore it.
这个问题十分重要，我们疏忽不得。
This is a matter of the utmost importance.
这是个极其重要的问题。
She has an exaggerated sense of her own importance.
她自视过高。
