Complete the sentences with the given words in their suitable 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）
2012 is a leap year. That’s why there are _____ days in February. (twenty-ninth)
It is clear that your schoolbag is much heavier than _______. (I)
Thousands of_______were lost in the terrible earthquake happened in Japan. (life) 
We are very ______to our teachers for their great help. (thank)
Your smile is the best way to show people your_______. (kind)
Wu Liangyong is one of the_____to get China’s Top Science Award this year. (win)
He needs a secretary who can also_________his life for him. (organization)
With the development of China, Chinese has become an international language and is______used all over the world. (wide).