It would be d and c hoped i helped!
Answer:
They host three or more distinct ecosystems at different elevations.
Explanation:
I checked it, and its right.
Explanation:
Since a double helix is formed by two paired antiparallel strands of nucleotides that run in opposite directions, and the nucleotides always pair in the same way (adenine (A) with thymine (T) in DNA or uracil (U) in RNA; cytosine (C) with guanine (G)), a (single-stranded) nucleotide sequence is said to be a palindrome