opener

n.开启者，开辟者；开具；开端

open sandwich, open to, open up, open verdict, open vowel, open-air, open-and-shut, open-ended, open-eyed, open-handed, open-handedly, open-handedness, open-heart surgery, open-hearted, open-minded, open-mindedness, open-mouthed, open-plan, open-work, opencast, opening, opening night, opening-time, openly, openness, opera, opera-glasses, opera-house, operable, operate, operatic, operatically, operating system, operating-table, operating-theatre, operation, operational, operations room, operative, operator,