任劳任怨

to work hard without complaint (idiom)

surname Ren / Ren County 任縣|任县[Ren2 Xian4] in Hebei

to assign / to appoint / to take up a post / office / responsibility / to let / to allow / to give free rein to / no matter (how, what etc) / classifier for terms served in office, or for spouses, girlfriends etc (as in 前任男友)

to toil / labor / laborer / to put sb to trouble (of doing sth) / meritorious deed / to console (Taiwan pr. [lao4] for this sense)

to blame / to complain