She made helpful comments on my work.

　　她對我的工作提出了有益的意見。

　　Role-play is helpful in developing communication skills.

　　角色扮演有助于提高溝通技巧。

　　Sorry I can't be more helpful.

　　對不起，我幫不上更多的忙。

　　Parents often feel helpless, knowing that all the hugs in the world won't stop the tears.

　　家長們常常感到無能為力，知道世上所有的擁抱也不能止住眼淚。