how long have you ___this book a.bought b.buy c had d buying为什么_英语解答

how long have you ___this book a.bought b.buy c had d buying
为什么

人气：495 ℃　时间：2019-12-07 01:18:05

解答

had.
buy只是个动作,不可能说买这本书这个动作需要多久,而是说你买了多久啦,用had是正确的.