我从来没有见过这样阴郁而又光明的日子。
So foul and fair a day I have not seen.
每一种化学结合完全且仅仅依赖于两种对立的力量，即正电和负电。
学习是一种超能力。
Certification standards are meaningless without rigorous enforcement and transparency.
Profitability and environmental stewardship can—and must—go hand in hand.
Beyond the spotlight of attention, the undercurrents of the subconscious are altering the riverbed.