三角形两边长分别为3和6，第三边是方程x²-6x+8=0的解，则这个三角形的周长是(   )

依次填入下面一段文字横线处的语句，衔接最恰的一组是(　　)。
相传，很久以前的一个月明风清之夜，天庭里几位仙女动了凡心，决定到人间玩一回。____________，____________，____________。____________，____________。____________，遂化成亭亭玉立的美人蕉，留在了凡间。这则传说仿佛证实了美人蕉的不俗。
①谁知这里飞瀑直泻，水清如镜
②随后弃船登岸，走进一线天内
③于是摘叶成船，折枝为桨，划船赏景良久
④仙女们情不自禁，宽衣解带，跳进潭中，追逐戏水
⑤她们按下云头，正好落在风景胜地长潭河畔
⑥很快，山鸟啁啾，天已放亮，仙女们却已回不了天庭

2，4，8，16，32，____，____

根据短文理解, 完成下列各题。

      One day, I was cooking with my friend Sandy in the kitchen. Suddenly, Sandy cut her finger. I went to her quickly. But to my surprise, I saw computer chips in her finger.

   “Now you know my secret, you have to die!” Sandy said and picked up the knife. “No, please, Sandy. Aren't we good friends?” I shouted. But before Sandy could say anything, she fainted.

    “Oh, Sandy!” I took her to hospital in a hurry. After a doctor checked her, he said, “I'm afraid we can't help her. Why don't you take her to a robot centre?”

      I hurried to a robot centre. A few days later, Sandy was well. She asked, ”Mary, why did you save me even after I tried to kill you? ”

“Because I'm sure you are my friend. Can you tell me where you are from?” “I'm from another planet. It's far from here. Thank you, my friend Now I see how friendly people are on the earth.”

      Two days later, a UFO came and picked her up. Since then I've never seen her.