根据问题出现的背景，代数实部可以接受从负无穷到正无穷的所有数值。

"The true alchemists do not change lead into gold; they change the world into words."

Persistence is key in mathematical research; many great results come from long struggles.

Food security is the cornerstone of national security, we must firmly grasp it in our own hands.

创新需要勇气和毅力。