proficiency  n.熟练,精通

与fact,fect,fict, feat, feit, fet, fit有关的英文单词≈to make, produce; to do, act; to perform

proficiency = pro(=before时间上的前) + fic(=to do做) + -iency(可作名词后缀)→ 比别人提前做完某事的能力→ n.熟练,精通。

Any of12 levels of proficiency at the grade of black belt in martial arts such as judo and karate.段在东方武术中，黑腰带的级别精通达12级中的任一级，如柔道和空手道

词形变化
名词复数: proficiencies

英英解释
名词 proficiency:
the quality of having great facility and competence
skillfulness in the command of fundamentals deriving from practice and familiarity同义词：technique

rejoice  v. 使 ... 欢喜, 高兴

re-,red-来自拉丁文前缀re，表示back(向后；还原),again(再次；表示强调),against (反向；相反)。

rejoice = re-(=again表示强调) + joi(=joy高兴)+ -ice(可作动词后缀) = 很高兴→ vi.感到高兴,充满喜悦

They all rejoiced to hear the happy news.他们都很乐于听到这个令人高兴的消息。

词形变化
名词: rejoicer 动词过去式: rejoiced
动词过去分词: rejoiced 动词现在分词: rejoicing
动词第三人称单数: rejoices

英英解释
动词 rejoice:
feel happiness or joy同义词：joy
to express great joy同义词：exuberate, exult, triumph, jubilate
be ecstatic with joy同义词：wallow, triumph