When a contour line crosses river it makes a v shape the open side or mouth of the v indaicates

Hello,

I think the answer is Downstream.

Hope this helps (:

the way that the mass of carbon can be conserved through cellular respiration is through a process/law called the law of conservation of mass which even tho it undergoes a process, mass is not be destroyed or changed

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.