279.I'm behind in my work.（我工作进度落后了。）

280.I won't buy your story.（我不信你那一套。）讲解

279.I'm behind in my work.（我工作进度落后了。）讲解

278.I'd like to try on this hat.（我想试试这些帽子。）

278.I'd like to try on this hat.（我想试试这些帽子。）讲解

277.If I had known that I could have helped you.（假如我早知道我就帮你了。）

277.If I had known that I could have helped you.（假如我早知道我就帮你了。）讲解

276.If I were in your shoes.（如果我站在你的立场上。）

276.If I were in your shoes.（如果我站在你的立场上。）讲解

275.I look forward to it.（我将期待着这一天。）