The structure of dna is held together by ?

A. purines pairing with pyridimines
B. hydrogen bonds between adenine and thymine
C. attraction between cytosine and guanine.
D. All of the above

B

Explanation:

nitrogenous bases on the two strands of DNA pair up, held together by weak hydrogen bonds.

it’s lava came from an explosive eruption

he movement of air through earth's or any planet's atmosphere is called wind, and the main cause of earth's winds is uneven heating by the sun. this uneven heating causes changes of atmospheric pressure, and winds blow from regions with high pressure to those with low pressure.

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