essentialities

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.

互联网

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.

互联网