His behaviour at the party was most regrettable.
他在宴会上的作为令人深为遗憾。
It was regrettable that such great issues had to be the thrust and parry of a general election. But at least the debate should be constructive.
如此重大的问题不得不成为大选中人们激烈辩论的议题，这很令人遗憾。可这场辩论至少应该是建设性的。
It's regrettable that you diddled away the whole afternoon.
真可惜，你把整个下午浪费掉了。
