Question: What are the signs or symptoms of hydrogen sulfide?
Paraphrase: What are the signs or side effects of hydrogen sulfide?
SPARQL (Wikidata): SELECT ?answer WHERE { wd:Q170591 wdt:P1542 ?X . ?X wdt:P780 ?answer}
Answer: headache, fatigue, irritability, coma, conjunctivitis, photophobia, apnea, convulsion, frostbite, insomnia, dizziness, eye irritation, tear secretion, Gastrointestinal distress, eye pain, respiratory irritation, cornea blistering