不明

unknown; unclear; obscure; indistinct; vague; ambiguous; unexplained; undefined; murky; dim; faint; hazy; nebulous; indeterminate; veiled; dark; dull; fuzzy; do not understand; be not clear

原因的

causal; causative; etiogenic

发热

fever; heat; heat up; become feverish; run a fever; generate heat; have a fever; give out heat; beam; pyrexia; febricity; feverish; hot; heated; febrile; fevered