好心人帮我翻译一下（初中的）英翻中，谢谢，不要给我翻译器的文章，

Waitress put a glass of water in front of him.”How much is an ice-cream sundae?”“Fifty cents.”the waitress answered.The little boy pulled his hands out and count a number of coins in it.”How much is a dish of plain ice-cream?”he asked.Some people were now waiting for a table and the waitress was a bit impatient.”Thirty-five cents.”was the answer.The boy counted his coins again,”I’ll have the plain ice-cream.”he said.The waitress brought the ice-cream,put the bill on the table,and walked away.The boy finished the ice-cream,paid the bill and left.When the waitress came back,she began cleaning the table and then she was surprised at what she saw.There,placed neatly beside the empty dish was fifteen cents——her tip