essential part
词形变化：
副词: essentially | 名词: essentiality |
同义词：
necessary | vital | basic | fundamental | important | indispensable | needed | required | requirement | necessity | urgent | elementary | primary | significant | constitutional | burning | organic | highlight | subjective | cardinal | virtual | principal | component | elemental | grave | key | lifeblood | essence | quintessence | prerequisite | need | want | requisite | of the essence | crucial | all important | substantive | all-important | inherent | radical |
反义词：