problematic：有疑问的，未解决的，未定的 

词根词缀：pro-前 +blem扔,抛 + -atic形容词词尾

• intelligent
• intelligentsia
• intelligible
• intemperate
• intend
• intense
• intensify
• intensity
• intensive
• intensive care unit
• intent
• intention
• intentional
• inter
• inter-
• interact
• interaction
• interactive
• inter alia
• interbreed
• intercede
• intercept
• intercession
• interchange
• intercity