painstaking：需专注的，需细心的

pain,疼痛，-s,复数后缀，taking,承担。比喻用法。

• felicitous
• felicity
• feline
• fell
• fella
• fellate
• fellow
• fellowship
• felon
• felony
• felt
• female
• feminine
• feminism
• femme fatale
• femur
• fen
• fence
• fencing
• fend
• fender
• feng shui
• Fenian
• fennel
• fenugreek