Have you finished(reading)this book为什么用ING形式

--- Have you finished reading the book? 英语翻译【】【】【】this month,I‘ll have finished reading this book. that,finished,have,book,reading,you 连词成句 现在完成时例句：I have finished reading the book,read要加ING? i have finished reading this magazine.can i s____with you? we have finished reading the book? 英语时态题have you finished _____(read)this book? Have you finished ___the book? You can keep the book until you ( ) A,have finished reading; M:Have you finished reading the book you bought last month? have you read this book?do you read this book?为什么疑问词要用have 而 after reading this book,you will have no -----solving these-