here are the structures i hope it helps
Answer:
primary, secondary, tertiary, and quaternary.
I believe the correct answer is A. Increases the rate of a chemical reaction. This is because they act as catalysts.
Marshmallows are probably so delicious because of several important factors. They are fluffy, soft, and oh-so sweet. They melt in your mouth and taste absolutely heavenly with chocolate and graham crackers. Or throw a couple in your hot chocolate. There's no wrong way to eat them and they're pretty cheap too.
<span>Unidirectional flow in the heart is ensured because the heart contains valves that prevent backflow.
These valves keep the flow of the heart going in one direction (hence the name "unidirectional").</span>
