essentialities的中文翻譯是什麼意思

Some essentialities in operation and maintenance of high speed trains are discussed.

論述了高速列車在運用檢修中的若干個基本問題.

There are many factors influencing spontaneous combustion in goaf and their relative essentialities are different.

採空區自然發火的影響因素很多,各因素之間的相對重要性不同.