That's a good idea.为什么不用an,难道这里的不定代词是用来修饰good?什么时候可以用 an+形容词+idea

That’s a good idea. that's a good idea 同义句 好主意.That's a good idea. That's a good idea.同义句That's a good idea.That __ __ a good idea. GOOD IDEAit's a good idea to learn 还是 that's a good idea to learn? Maybe that's a good idea(同义句转换)That _____ _____a good idea That's a good idea 和 It's good idea 怎么区分 That's really a good idea!翻译这句话 求教：That's a good idea． 啥意思内 ( ) ( ) some flowers. Oh,that's a good idea. is idea that a good(.) that's a good idea和that's right的区别you are tired.you should have a resta that's a good idea b that's right It's a good idea I'm not sure that's a good idea中that's 为什么带s It's sunday today.What a( ) having a picnic? That's a good idea()处填啥 That's a () excellent idea. -Tomorrow is Sunday.Let's go to watch the movies together.-That sounds______a.like good b.like a good idea c.likes good d.likes a good idea Let's go shopping right now.(作肯定回答) ________.That's a good idea.