help的形容詞詞形式是？

　　Role-play is helpful in developing communication skills.

　　角色扮演有助于提高溝通技巧。

　　When you go to concerts, it's helpful to read the programme.

　　去音樂會的時候，看看節目單是有幫助的。

　　An A to Z of careers gives helpful information about courses.

　　一本按字母順序排列的職業手冊，提供了有助于課程選擇的信息。

　　Having the right equipment at hand will be enormously helpful.

　　有合適的工具在手邊將會極為有用。