Mr . Smith teaches English in a high school He has two daughters . They aye twin( 双胞胎 )sisters . Mr . Smith calls them Lily and Lucy . Jim and Alex are Mr . Smith’s students . They often go to see the twins and play with them at home . They often buy something for Lily and Lucy . One Sunday , they go to Mr . Smith’s home . When the twins see Jim and Alex , they are happy . Jim asks Lucy , “How old are you , Lucy?” “Three 。 ”she answers( 回答 ) . Alex says , “Lily and Lucy , these are bananas . Would you like them . '?Well , I have a small question( 问题 ) . If one of you can answer well , I will give her one . ” “I have two bananas , now I eat one . How many bananas do I have ,then?” “One . ’’Lily says . Lucy answers , “Two . ’’ “Two?”Jim says , “Why ?” “Oh , one is inside( 在里面 )and the other is outside( 在外面 ) . ”