Not only that, but when David's team  experimentally fixed the methylation patterns, preventing them from changing, the blind mice didn't regain their vision.

不仅如此， 当 David 的团队通过实验固定甲基化模式以防止它们发生变化时，失明小鼠并没有恢复视力。

But today I want to talk about the importance of stars for early seafarers, about how the fixed patterns of stars were used as navigational aids.

但今天我想谈谈星星对早期航海者的重要性，关于星星的固定图案是如何用作航海辅助工具的。