essential element

• 必需元素,主要元素

essential element的用法和样例：

例句

1. The theme is chosen in view of the human reliance on water as an essential element of life.
   选择此题材是由于水是人类赖以为生的一个主要元素。
2. Soon,the dance elements faded into the background and improvisation became the key element of the music.
   但不久原本这些舞蹈的元素就隐退了，取代之而成为爵士乐主要元素的便是即兴演奏。