CBSE Class 9 Answered

Hi Prajwalraut,

The lines mentioned by you are parts of two different ideas.

I slip, I slide, I gloom, I glance,

  Among my skimming swallows ;

mean 

I (the brook) move around in slipping and sliding motion passing through the dark and bright parts of the place while my swallows skim my surface for food.

and

I make the netted sunbeam dance

  Against my sandy shallows.

mean

The beams of the sun pass through my waves which create a netted obstruction for them. In the process, the beams scatter and sparkle as if they are dancing at my bed.