1. In a questioning format 
2. With curiosity
   - curiously, inquisitively

See also: interrogative

• unprincipled
• unprintable
• open-end wrench
• open-ended
• open-eyed
• open-face sandwich
• open-faced
• open-heart surgery
• open-hearth
• open-hearth furnace
• open-hearth process
• open-minded
• open-mindedly
• open-mindedness
• open-plan
• open-source
• openbill
• opencast
• opencast mining
• opencut
• opened
• opener
• openhanded
• openhandedness
• openhearted