即这里的不变性特指：推理时不随输入变化而变化，但在训练过程中，矩阵是可以根据需要去做梯度下降而变化的Most species are reasonably very similar. All four are very extensive and narrow-bodied, with astonishingly slender heads for venomous species. Two of the four have shiny green scales, a single has mo