抽象允许一种自由，而具象有时无法做到。
Abstraction allows for a kind of freedom that representation sometimes doesn't.
I'm not perfect, but I'm striving every day to be better than I was yesterday.
成功不要紧,失败不致命。继续前行的勇气,才最可贵。
The primary rules of obligation are those that require or forbid certain actions.
Investing in cleaner coal technologies is an investment in our future.
