Which of the following levels of organization is lower than the population?

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products

instead of copying and pasting things off of tests or work done on computer which im sure you did, try and read over the question carefully