The answer is <span>c.CS; US.
In classical conditioning, a new behaviour is learned via association. The stage before conditioning involves: 1. unconditioned stimulus (US) which produces an unconditioned response, and 2. neutral stimulus (NS) which has no effect on a person and produce a response only when paired with </span>unconditioned stimulus. During conditioning, neutral stimulus (NS) and unconditioned stimulus (US) pair and neutral stimulus becomes a conditioned stimulus (CS). In other words, <span>the ns becomes a <u>CS</u> after it reliably signals the impending occurrence of the <u>US</u>. </span>
There is a difference in color between the reactants and the product. Also, a gas and a solid bread loaf were produced, compared to the liquid or powder forms of the reactants.
I believe the answer is <span>small annual plants
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<span>Small annual plants will easily grow after a flood since it was small and rapidly growing. They also died fast, which makes them reproduce quickly. If the condition is harsh with less soil, l</span>ichen will be the most easier to survive. Pine and oak are strong trees that will be formed last.
Here is the answer that would best complete the given statement above. Specialized cells in plant roots ensure that they grow down into the soil to find water and nutrients. This plant response by specialized cells is calledGRAVITROPISM. This is also known as geotropism wherein plants grow in response to gravity. Hope this answer helps.