infinity

孩子们的笑声似乎回荡至无限。

The children's laughter seemed to echo into ___infinity.

数学中的无穷概念让我们思考空间的无限延伸。

The concept of ___infinity in mathematics makes us think about endless space.

宇宙中的星星数量接近无限，根本无法计算。

The number of stars in the universe is close to ___infinity, impossible to count.