When to meet senesce?

什么时候会开始衰？

Chillness intensified the senesce of leaves, enhanced the MDA content and the O2-. produce rate, this was more evident in Shanyou63.

低温处理加剧了叶片的衰，MDA含量和O2-产速率上升，九的升幅较汕63小。

But hang on -- how do we know that radioactive atoms don't senesce?

但是，听清楚了—我们怎么知道放射性原子不衰？