1.The human race has enough weapons to annihilate itself.人类有足够的武器灭绝自己。
2.Can the human race carry on expanding and growing the same way that it is now?人类能继续像目前这样扩张和增长下去吗?
3.This nameless person pushed the human race over a historic threshold, for it was in that year that mankind became, for the first time in its history, a predominantly urban species.这个无名的人把人类推向了一个历史性的门槛,因为正是在那一年,人类首次成为主要居住在城市的物种。