用方框中所给单词的适当形式填空，使句子通顺，正确。每词限一次。

thin  twelve  cost  south  develop

小题1: Mr. Green lives on the __________ floor of the building.
小题2:After exercising for a few months, she is a little           than before.
小题3:How much does it          to fly to Shanghai from Fuzhou?
小题4:Many foreigners are surprised at the rapid _______________ of China.
小题5:It rained heavily in the          of Zhejiang Province last week.