新概念问题：1.Visitors have been asked to keep the woods clean and

问题描述：

新概念问题：1.Visitors have been asked to keep the woods clean and tidy.请问这是现在完成时态吗?
主语+have+动词过去分词为什么这里面有两个过去分词?been asked?

1个回答分类：英语 2014-10-29