thanks  i appreciate your help i learned a lot  and i will do it 

You're halfway there. You can't just follow one side of the snake's body with shading, as the lit side is alternating. Decide on a light source and stick to it. Edit here.

You can also use shading and highlits to convey the inward curving of the 'wings', and their thinness. Consider using refs for help with the voulme on this.

You might also remove most of the black inside outlines, and try to use lighting to give some volume to the segmenting (segments would be unrealistic for a snake, ok for a fnake I think).

Then since snakes are scaly, you might have a little dithering, but be sure to apply this at the end, after your shading is consistent.

Keep up the good work!