He is always on time and strictly follows the rules, being very punctilious about his behavior.

### 解释 punctilious 是由拉丁词根 punctum（点）加上后缀 -ilious 构成的形容词，字面意思是"像点一样精确的"，引申为"一丝不苟的、严谨的"。 这个词强调对细节和规则的极度关注，常用于形容那些严格遵守礼仪规范或行为准则的人。