that's/there's an ideaspokenLIKE somebody OR something used to say that you like what someone has just suggested 好主意〔用于表示赞同某人的建议〕 ‘Why don’t you invite Paula to come with us?’ ‘There’s an idea.’ “你为什么不邀请葆拉和我们一起去?”“好主意。”
→ that’s/there’s an idea at idea(4)