—Don't            late, Betty. You have to go to school early tomorrow.

—OK, Morn. I'll go to bed right now.

下列属于最简二次根式的是（　　）

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                                                                                      陋室铭
      山不在高，有仙则名。水不在深，有龙则灵。斯是陋室，惟吾德馨。苔痕上阶绿，草色入帘青。谈笑有鸿儒，往来无白丁。可以调素琴，阅金经。无丝竹之乱耳，无案牍之劳形。南阳诸葛庐，西蜀子云亭。孔子云：何陋之有？