I don't think you should ever regret anything. Everything happens for a reason.
无人机最激动人心的应用还没有被发明出来。
A law of nature， lex naturalis， is a precept or general rule found out by reason， by which a man is forbidden to do that which is destructive of his life or takes away the means of preserving the same.
La literatura es un espejo que refleja la sociedad en la que vivimos.
The most sustainable solutions often come from the simplest ideas.