How do you say post office in Chinese?
— 郵局, 邮局 (yóujú)

Generic synonyms for post office in Chinese
arm胳膊 (gēbo), 胳臂 (gēbei), 手臂 (shǒubì), 臂膀 (bìbǎng)
branch支 (zhī), 樹枝, 树枝 (shùzhī)