During which phase of the cell cycle is a cell's dna copied?

The answer to this question will be "Mitosis." During Mitosis the DNA cell is replicated during the cell cell cycle. Mitosis is basically cell division that equals two copied daughter cells with the same amount of chromosomes as each other during the cell cycle.

Hope this helps.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

enhanced global partnerships and exploration capabilities may advance international preparedness for protecting the earth from catastrophic events such as some asteroid strikes, advancing collaborative research on space weather and protecting spacecraft by developing new means for space debris removal.