听力资源简介：

helpful　
(a.) 乐于助人的；有帮助的

Thank you for cleaning up. You're so helpful.
谢谢你帮忙打扫，你真热心。

moody　
(a.) 情绪不稳定的

Marvin's really moody. One day he's happy, and the next day he's sad.
马文真的很喜怒无常，前一天还很开心，隔天却很忧伤。