It’s the second one. H,D,C,F,B,G,E,A
The two gasses that make up 99% of the earth's atmosphere are nitrogen and oxygen.
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Answer: double helix
Explanation: The double helix of DNA is, like its name implies, in the shape of a helix which is essentially a three dimensional spiral. The double comes from the fact that the helix is made of two long strands of DNA that are intertwined—sort of like a twisted ladder.
