Annelids, like the earthworm, and arthropods, like insects or spiders, have three main structures in their nervous systems:
-a brain, a dorsal nerve cord, and a ventral nerve cord
-a brain, segmented ganglia, and a ventral nerve cord
-segmented ganglia, a dorsal nerve cord, and a ventral nerve cord

The answer is Segmented ganglia, a dorsal nerve cord and a ventral nerve cord.

Explanation:

In case of invertebrates like annelids and arthropods the nervous system is not so well developed. The nerve cells are not organized into brain but they have collection of nerve cells which makes ganglia. Annelids are both externally and internally segmented whereas arthropods show only external segmentation. The presence of ganglia in each segment gives the name segmented ganglia. Along with this they have nerve cord running from anterior to posterior end. The one present on the dorsal side is called dorsal nerve cord and the one present on the ventral side is called ventral nerve cord.

the water is warmed up by the sun and then it evaporates into the atmosphere. the sunlight warms the water by its heat. water is then cooled down and condensation takes place. the water then finally returns back to the earth by the process of precipitation in the form of rain or ice.

explanation: