"Completely thorough" 可以用 "thoroughly comprehensive" 来表达。这个短语是由 "thorough" 和 "comprehensive" 两个词组合而成的。
"thorough" 意为 "彻底的"，表示事情做得非常详尽，不漏细节。
"comprehensive" 意为 "全面的"，表示事情做得非常全面，不遗漏重要的部分。
例句：
The report was thoroughly comprehensive, covering every aspect of the project.
(报告非常全面，涵盖了项目的各个方面。)
The examination was thoroughly comprehensive, testing students on everything they had learned.
(考试非常全面，考察学生所学的所有知识。)