Complete the sentences with the given words in their proper forms (用括号中所给单词的适当形式完成下列句子。每空格限填一词)
Climb up to the ____ floor, and you can enjoy a better view. (eleven)
____ , Grace made up her mind to live abroad with her daughter. (final)
It is a very ____ book for language learners to improve writing skills. (use)
Don't worry about your son. He is old enough to be independent and live by ____ . (he)
The movie KungFu Panda II is sure to ____ a large number of teenagers. (attractive)
If you don't go on a diet, it is ____  for you to lose weight. (possible)
The local people had to move away because of the serious ____. (pollute)
The great ____  gave his first show in Shanghai and the tickets sold out in minutes. (art)

如图1是边长为1的六个小正方形组成的图形，它可以围成图2的正方体，则图1中小正方形顶点A，B围成的正方体上的距离是____ 

某可燃化合物×完全燃烧的化学方程式为X＋O₂→CO₂＋H₂O（未配平）则X不可能是（　　　　　）

已知f（x）=xlnx﹣ax，g（x）=x³﹣x+6，若对任意的x∈（0，+∞），2f （x）≤g′（x）+2恒成立，则实数a的取值范围为（　　）