英语脑筋急转弯,You haven't sharpened your pencil ,but you feel it i

英语脑筋急转弯,
You haven't sharpened your pencil ,but you feel it is shorter ,why?What can you find in the middle of a box?A man went into a lion cage ,but he didn't get hurt ,why?A pair of shoes costs thirty dollars .How mach is one shoe?Why can Mr.Wang's horse eat Mr.Zhang's elephant?实在做不出来了,用英语回答哦,