regrettable的解释
a. 可叹的,可惜的,抱歉的
regrettable的例句
It is regrettable that few people shall walk today because of the development of traffic facilities.
由于交通设施的发展，现在很少人愿意步行，这是很可惜的。

It's regrettable that you diddled away the whole afternoon.
真可惜，你把整个下午浪费掉了。