不可或缺

To try or attempt to do something. It often implies a deliberate effort to achieve a goal, sometimes with uncertainty about the result.

To record or document something in writing or on other media; a written record of events.

The main idea, gist, or central theme of a text, speech, or lecture.

A version of something that differs in some way from others of the same kind or from a standard. Often used in biology, linguistics, and art.

A systematic theory or doctrine, especially one held by a particular group or individual in science or philosophy.

A figure of speech in which a word or phrase is applied to an object or action to which it is not literally applicable; a metaphor or analogy.

Soon after; following that. Used to describe an event occurring immediately after another.

Up to this time; until now. It is often used to emphasize a record, a state of affairs, or the extent of something up to the present moment.

To state something publicly or officially, often without providing proof yet; to claim or assert.

Extremely good; outstanding; far above average in quality or performance.