难题

To divide or partition something into distinct sections or categories according to a certain standard.

To state something again clearly and strongly to emphasize its importance or to ensure it is understood.

To borrow and read books or other materials, usually from a library.

Generally recognized or universally accepted as being true, valid, or of a certain quality by the public or a specific group.

The state of being limited or having restrictions; the qualities that prevent someone or something from being as effective as they could be.

A comparison between two things that are similar in some way, often used to explain a complex idea by comparing it to something simpler.

And then; after that; a step further; used to show progress in action or development.

To go against or be contrary to (something). Used to describe conflicting ideas, evidence, or laws.

To diminish the importance, visibility, or intensity of something; to fade out.

To include or incorporate a wide range of things or everything within a specific category; to sweep up all items.