hit and run (the military technique of attacking one place and then quickly moving to another before defenders can react)

the best or top person, such as the best performer in a company, or a leading expert

Have a nice day!

one person

花一匁: a traditional Japanese children's game that is similar to the game red rover

生命中心主義: biocentrism (cosmological theory)

一味同心: people working together with one mind

one day, 24 hours / the daytime, the period from dawn until dusk / (figuratively) a short period of time / one day, someday, an unspecified day / the first day of the month

(linear algebra) positive-definite matrix

(linear algebra) positive-semidefinite matrix