constructive

a. 建设性的,构造上的,作图的

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。

I can not figure out why they ridicule this constructive suggestion.

我弄不懂他们为什麽嘲笑这一建设性建议。