同一元素的原子在质量和性质上是相同的。
You will never reach your destination if you stop and throw stones at every dog that barks.
真相很少是纯粹的，也从不简单。
It will take about a thousand million million million million years for the Earth to run into the sun, so there’s no immediate cause for worry!
"I don't think about the negatives. I just think about the positives."
