Questions

EBITDA stands for earnings before interest, taxes, depreciation, and amortization. EBITDA came into wide use among private capital firms, wanting to calculate what they should pay for a business.

Oxford

"The moon smiled at me" is the example of personification in the given options.

Personification is a technique in which we give objects human traits like emotions, gestures, speech,... by using metaphor. 

Here moon is an object which cannot smile but using metaphor sense, we gave that sense to it.

The one word substitution for Of outstanding significance is monumental which has a meaning of great in importance, in size or any such characteristic.

Silicon carbide is used in Cutting very hard substances.

An index is an optional structure associated with a table to have direct access to rows, which can be created to increase the performance of data retrieval. Index can be created on one or more columns of a table.