Word Roots are a Part of History. "Histories Make Men Wise" -- Bacon.

sedulous

working hard and steadily (sometimes without using tricks); diligent; persistent

勤勉的, 勤苦工作的, 聚精凝神的

See also: sedulous should not be dissected as sed (sit, settle) + ul (diminutive) + -ous (full of). sed here is not the same as sid as in assiduous = as- (to) + sid (sit, settle) + -uous (full of; tending to). See also assiduous

sedulous = se- (apart 分离开; extended further to mean not, without 引申为不， 没有) + dul (trick 诡计) + -ous (full of 充满);
sedulous = not using trick 不施诡计的;
sedulous = extended further to mean working very hard and steadily without using any trick 引申为勤勉的, 勤苦工作的

Note: You may sometimes find that a vowel such as o is often inserted between two roots, as o inserted between phon and graph in phonograph = phon + o + graph, the reason is for easy pronounciation. Another example is archaeology = archae + o + logy