[答案]
(1)Whatareyougoingtodothisafternoon(2)Whatbookdoyouwanttoborrow(3)Why/Whydoyouthinkso(4)Whatdoyouthinkisthemostusefulinvention/Howaboutyou/Whataboutyou(5)Goodidea/That'sagoodidea/Soundsgood/great
[解析]
(1)根据答句"比尔,今天下午我要去借书,这里要询问"你今天下午要去做什么。
(2)根据答句"我想借一本关于发明的书。"可知?"故填What book do you want to borrow。
(3)根据答句"因为它使我们的生活更方便。"可知?"故填Why/Why do you think so。
(4)根据答句"我认为汽车是最有用的。"可知。故填What you is most invention/How about you/What about you。
(5)根据后文"我希望你能梦想成真。"可知。故填Good idea/That's a good idea/Sounds good/great。
[点评]
本题考查了"询问   ",属于"基础题",熟悉题型是解题的关键。