Answer: D) Pulmonary and aortic valves.
Explanation
There are two main heartbeats from a healthy heart.
The first beat is called the S1 or the lub, and it occurs when the atrioventricular valves (comprising the mitral and tricuspid valves) close.
The second beat is called the S2 or the dub, and it occurs when the semilunar valves (comprising the aortic and pulmonary valves) close.
Listening for heart beats is an essential part of cardiac auscultation.
Answer:
Photosynthesis is the process in which light energy is converted to chemical energy in the form of sugars. In a process driven by light energy, glucose molecules (or other sugars) are constructed from water and carbon dioxide, and oxygen is released as a byproduct.
A. when evaluating a source for reliability, if they are talking about a product from a company that sponsors them they may not be honest, or if they are sponsored by a reliable company they can be trusted it depends what way you look at it.
It is practical knowledge in the sense that we know why some parts of the world are inherently risky to live in. Even though volcanic eruptionis, earthquakes and tsunamis are difficult to predict, it makes sense to have building codes and emergency plans that take this into account.
It is science’s response to the beliefs that natural catastrophes (volcanism, earthquakes and tsunamis) are divine punishments for the evil ways of some individuals.
Even if you will never use or apply this knowledge, knowing about the theory of plate tectonics gives you a current scientific perspective on what we know about the natural world.
It is a good example of how scientific theories proceed by trying to fit several observations into a coherent explanation.
Learning about the observations that needed to be made and explained for the theory to win over scientists helps caution you against people who adopt belief systems without questioning the myths told to them, or those who try to profit from ignorance of how nature actually works.
When it is well taught, it should convince you that, like any scientific theory, plate tectonics is a “work in progress”. New discoveries continue to be made, and it takes creative and logical thinking, debate and a quest for more observations in order to determine which ones prove or challenge the current theory and which ones may lead to its refinement.
<span>Actually energy is the capacity to do work. It is not moving. It is transmitted, propagated, dissippated, or radiated. It depends upon what type of energy it is. Heat energy is dissippated through conduction, convection or radiation. For conduction the particles must be in contact. For convection the particles which posses the energy must ba able to move about. For radiation, even without a material medium the energy is transmitted in the form of waves. Eg. energy from the sun. When a stone is dropped in still water the energy is imparted to the water surface. This energy is distributed all over the water surface in the form of circular waves (ripples). Electrical energy - through conducting wires or electromagnetic radiation. Light energy & sound energy are through waves.</span>
