You will be given a definition of a task first, then some input of the task.
In this task, we ask you to write an answer to a question that involves events that may be stationary (not changing over time) or transient (changing over time). For example, the sentence "he was born in the U.S." contains a stationary event since it will last forever; however, "he is hungry" contains a transient event since it will remain true for a short period of time. Note that a lot of the questions could have more than one correct answer. We only need a single most-likely answer. Please try to keep your "answer" as simple as possible. Concise and simple "answer" is preferred over those complex and verbose ones.

Sentence: This approach has been echoed by Lev Landau and Evgeny Lifshitz, and others, and has become standard. 
Question: Is the approach accepted by others?
Output:
yes.