Answer: Carbon
Explanation: Organic compounds are those made by carbon atoms that link to other carbon or elements such as nitrogen, hydrogen or oxygen with covalent bonds.
The presence of these compounds were associated with living things, because most of them are produced by plants or animals. However nowdays substances like polymers and other synthetically made molecules can also be considered as organic since they are made of carbon.
Veins is the correct answer
Answer is: this sample of sand is heterogeneous mixture.
Heterogeneous mixture is not uniform in composition (in this mixture different metals and minerals), but proportions of its components (in this mixture particles of different colors, small pebbles) vary throughout the sample.
Mitosis hope that helps i tried:)