One reason for the time delay is because the four paths the light took were different lengths.

延迟的原因之一是因为光线所走的四个路径的长度不同。

In a new experiment, this dendritic cell is given a choice of four paths of different widths.

在一项新实验中，该树突细胞可以选择四种不同宽度的路径。

And Martin is going to share what he thinks are the four paths that banking reform could take in the future.

马丁将分享他认为未来银行业改革可能采取的四种途径。