词根词缀：grat-, gra-, grac-

【来源及含义】Latin: beloved, pleasing, dear, agreeable; grateful, thankful, pleased

【同源单词】agree, agreeable, agreeableness, agreeably, agreement, congratulate

词根词缀：tacit-, taci-, tace-

【来源及含义】Latin: silent, silence; unspoken; quiet

【同源单词】Qui tacet consentit, reticence, reticent, tace, tacenda, Tacet