Help me on this question and NO LINKSS

the first one

Explanation:

parasites are usually much more numerous than their hosts, but predators are usually less numerous than their prey.

Im not 100% sure its just what i think it is

I mostly think it's B, because parasites give effects on their host but not at the same time.

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