This sentence should end with an exclamation mark.
Tips
memory
Parses as 惊 (startle) + 叹 (sigh / exclaim) + 号 (mark), the punctuation for surprise and exclamation. Synonym 感叹号 (gǎntànhào) is more common in mainland textbooks; 惊叹号 leans Taiwanese / Cantonese-influenced.
