Keep in mind that each source point on the extended source is incoherent with respect to the others . 要记住，扩展光源上各个点之间彼此都是不相干的。
2.
Extended sources of this sort are generally referred to as incoherent but this description is somewhat misleading as we shall see in a moment . 这种扩展光源一般叫做不相干的。但是我们不久就会看到，这种叫法会使人产生一些误解。
3.
The housing department will extend source separation facilities to all public housing estates by may 1999 房屋署将于本年五月前将废物分类计划扩展至所有公共屋。
