| inquire(verb, examine, challenge, doubt, seek) |
| ask(verb, doubt, question, search, suspect) |
| conduct research |
| query(verb, examine, challenge, doubt, seek) |
| investigate(verb, examine, challenge, seek, search) |
| question(noun, verb, doubt, search, ask) |
| examine(verb, challenge, doubt, question, seek) |
| interrogate(verb, examine, challenge, doubt, question) |
| seek(verb, examine, challenge, search, test) |
| pry(verb, examine, challenge, seek, search) |
| wonder |
| demand |
| probe(noun, verb, examine, challenge, seek) |
| quiz(verb, examine, challenge, doubt, question) |
| catechize(verb, examine, challenge, doubt, question) |
| challenge(verb, dispute, examine, doubt, question) |
| hit up(verb, expression, examine, challenge, doubt) |
| knock(verb, examine, challenge, doubt, question) |
| make inquiry(verb, expression, examine, challenge, seek) |
| troubleshoot |