清朝末年，杨昌浚写了一首关于玉门关的诗。曰：“大将筹边尚未还，湖湘子弟满天山．新栽杨柳三千里，引得春风度玉关”，这首诗里将春风引到玉门关的大将是（　　）

    Mr. Brown lives on Green Street now. He wants to send a postcard(寄明信片) to his pen friend in Toronto, but he doesn't know where the post office is. “ where is the post office？” he asks his new neighbor Joe. “I want to send a postcard to Toronto.” “The post office is quite far from here，” answers Joe. “If you only want to post some letters(信件) or postcards, you needn't go to the post office. You can put them into a mailbox（信箱）down the street.”

植物细胞A和植物细胞B经过杂交及组织培养，下列说法不正确的是

运用适当的方法可以保存食品．下列叙述正确的是（    ）