先天下之忧而忧，后天下之乐而乐(宋·范仲淹《范文正公集·七·岳阳楼记》)

be the first to worry about state affairs and the last to enjoy oneself;be the first to bear hardships and the last to enjoy comforts

• infidelity
• infiltrate
• infinitesimal
• infirmity
• inflame
• inflamed
• inflammable
• inflated
• infliction
• infraction
• infringe
• infuriate
• infuse
• ingenious
• ingenuity
• ingenuous
• ingest
• ingrained
• ingrate
• ingratiate
• ingratiating
• ingratitude
• ingredient
• ingress
• inhale