Circle the correct answer sold cannot travel through A )solid B )empty space C )liquid D )gas

answer:   option a) glucagon was secreted by his pancreas before he ate the cookies because blood glucose was low. insulin was secreted after he ate the cookies because his blood glucose was high.

explanation:

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.

it is a. i hope this .