They started to play the piano one or two hours ago.(改为同义句)

an hour or two ago
再问： they have played piano for one or two hours 追问They started to play the piano_______ _________ _________
再答： 究竟是哪个题？！ they have played piano for one or two hours 怎么不同于原题？！
再问： They started to play the piano_______ _________ _________
再答： one or two hours ago
再问： 三个空
再答： 三空是没法表达“一两个小时以前”的 如果是“two hours ago" 与原句有出入