请帮看下我的另一个关于"what they could not find they would 问题

请帮看下我的另一个关于"what they could not find they would 问题 Search as they would,they could find nobody.这个句子从句中的助动词为什么用w They said they would do what they could do （）（keep）the river 关于虚拟语气的问题 would not have found would not find They could not find any strange things when they came into t 英语翻译If these walls could talk,baby what would they say they' do they say what they would 完形填空They could not find ＿(something)＿(usual). they gathered him all the dry stiks they could find. What Would They Say 歌词 英语翻译这个句子是：I could not even be certain if they would recall s They didn't know where they would find their lost kid的同义句转换