" n.b." , nota bene, means " note well" , means very important point.

“注意。” , nota bene，意思是“记好”，意思是非常重要的一点。

If somebody in the lecture says " n.b." or " nota bene" , make sure you write down what he or she says.

如果讲座中有人说“n.b.”或“nota bene”，确保你记下他或她说的话。