用方框中所给单词的适当形式填空。(每小题1分，共5分)

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 Fujian Province last week.