第20题: [单项选择]Questions 22 to 25 are based on the conversation you have just heard.A. She makes the keypad dirty. B. She always drops crumbs off the computer keyboard. C. She always eats off a toilet seat. D. It is not clean. 参考答案:D 答案解析:[解析] 22-25 M: Hi, Jenny, why are you still eating while you are using the computer W: Why I