essentialities的中文翻译是什么意思

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

论述了高速列车在运用检修中的若干个基本问题.

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

采空区自然发火的影响因素很多,各因素之间的相对重要性不同.