题目内容：

第二节：语法填空

In the days when an ice cream cost much less, Tom, __11______ 8-year-old boy, entered a hotel coffee shop _12_____ sat at a table. A waitress put a glass of water in front of him. "How much is an ice cream?" "Fifty-cents," replied the waitress. The little boy pulled _13_____ right hand out of the pocket and studied a number of ___14___ in it.

"How much is a dish of plain ice cream?" he asked. Some people were now waiting for her service and the waitress grew a bit __15_____ (patience). "Thirty-five cents," she said _16_____ (rude). The little boy carefully counted the coins _17_____. "I will have a plain ice cream," he said. The waitress walked _18______. The boy finished the ice cream, paid the cashier and left. It was not long _19_____ the waitress came back and then she began to wipe down the table and suddenly was surprised at what she saw. There, _20_____ (place) neatly beside the empty dish, were two nickels and five pennies --- her tip!