Which kind of twins always results when two different sperm fertilize two eggs?

What does the body do during the resistance phase of the gas model? options: a) it prepares to fight danger or run from it. b) it identifies the primary source of danger. c) it begins to return responses to normal. d) it repairs itself from fatigue and stress.

Avirus consisting of a single strand of rna, which is transcribed into complementary dna, is a ) proteaseb) retrovirusc) rna replicase virusd) nonenveloped virus

If you were running a marathon, which type of muscle fibers would be most useful to you? a. slow-twitch b. fast-twitch, type i a c. intermediate-twitch, type ii b d. slow-intermediate twitch, type i b select the best answer from the choices provided. a b c d