63, C
64 a
65 C
My guess GOODLuck buddy
By ball bearing, lubrication, polishing, adding grease etc
I'm thinking it's D, They have homologous chromosomes.
Answer:
13000 would be avalable because 10% is taken every time it is eaten so 65,000 with 10% taken out twice (20% of 65,000) is only 13,000 kcal available to the secondary consumers.