to focus and work hard for a long time
усердно и долго работать, сосредоточившись (usyeradno i dolgo rabotat sosredotochivshis)
"He kept his nose to the grindstone and got promoted."
"Он усердно работал и получил повышение." (on usyeradno rabotal i poluchil povyshenie)
Very quickly, almost instantaneously.
to keep persevering and not give up
to do what is expected or promised, especially in difficult...
kept secret or very confidential
Taking an irreversible step with serious consequences.
free from worries or problems
