adept：熟练的，老练的，精通的 

词根词缀：ad-加强意义 +ept(-apt-)适合→能干

• improvement
• improvident
• improvise
• imprudent
• impudent
• impugn
• impulse
• impulse buying
• impulsive
• impunity
• impure
• impute
• in
• in-
• inability
• in absentia
• inaccessible
• inaccuracy
• inaccurate
• inaction
• inactivate
• inactive
• inadequacy
• inadequate
• inadmissible