就是阅读理解有点难哦！！

thank you very much

感谢楼主分享，下载来看看

课件很精美，内容很丰富，谢谢楼主！

thank you very much!!!!!!!!!!!!

{:1_31:}

一直觉得这个单元很难，参考参考！！！

Thank you very much.

thank you very much

参考了。这个单元的内容好多，好复杂啊