大学英语： nucleus n. 核，核心，中心;起点，开始

These young people formed the nucleus of the internet bar. (这些年轻人成了网吧的核心。)

The strange behavior of the absent-minded professor became the nucleus of all the stories.(“心不在焉”教授的奇异举止成为所有故事的中心内容。)

12. agricultural adj. 农业的

agriculture n. 农业

More and more modern agricultural methods are used in that village.(在那个村子里，人们越来越多地使用现代农业方法。)

The agricultural production is on the rise this year. (今年的农业生产呈上升态势。)

His solution greatly improved the agriculture in this area. (他的方法极大地推动了这一地区的农业发展。)

13. industrial adj. 工业的，产业的

industrialize v. (使)工业化

The industrial output of this city doubled last year. (去年这个城市的工业产量增加了一倍。)

The Industrial Revolution influenced the whole world. (工业革命影响了全世界。)

The country has been steadily industrializing. (这个国家一直在稳步实现工业化。)