the forelimbs of humans, cats, and bats have a number of detailed similarities in their construction. what best explains these similarities?

answer: 21

step-by-step explanation:

divide 630 by 30. 30 goes into 630 21 times

fossil's are like over rated rocks like low key not gonna lie i don't get why we can't just call them old rocks like for real i mean i call my grandpa and grandma that smh

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.