The interplay between syntax and semantics is central to the study of formal languages.
我们是生存机器——盲目编程的机器人车辆，旨在保存被称为基因的自私分子。
"With a library you are free, not confined by temporary political climates. It is the most democratic of institutions because no one - but no one at all - can tell you what to read and when and how."