我不知道第三次世界大战会使用什么样的武器，但是我知道第四次世界大战会使用木棍和石块。
Understanding the fundamental forces of nature is essential to comprehending the cosmos.
The world always seems brighter when you've just made something that wasn't there before.
The most perfect education, in my opinion, is such an exercise of the understanding as is best calculated to strengthen the body and form the heart.
