Al is tough-minded. He marshals history to make his argument, and countless examples of civilizations changing course and attitudes midstream roll off his tongue.
戈尔是不随便说话的，他引用历史来支持主张：娓娓道来无数文明的衰落和错误态度的关系。
2
However, all of them had a very sharp tongue and were very ruthless, tough and even acerbic in criticizing other's works.
然而，他们的批评都非常尖锐，在批评中每个人表现得十分无情、强硬甚至尖刻。
3
You've got to be tough to do the little things like biting your tongue, waiting your turn and putting up with fools.