B)<span>When you listen to the heart sounds, you are hearing the flow of blood which stops abruptly when a heart valve closes. This produces the "lub-dub" sounds. 1st heart sound (when the Mitral Valve closes) as the ventricle contracts (systole) and then 2nd heart sound (when the Aortic Valve closes) and the ventricle starts to fill again (diastole)
</span><span>The pulse is the wave of pressure you can feel through the artery walls. This denotes systole.
</span><span>The ECG's QRS complex is the electrical signal that tells the Ventricles to contract. You can see that the QRS occurs right at the beginning of systole and triggers Isovolumetric contraction.
</span><span>So the QRS on the ECG, the pulse wave you can feel (ie. the rise in aortic pressure) and the 1st heart sound all signify SYSTOLE.
</span><span>there a delay between systole of the ECG and the resulting pulse felt in the finger (R-Pulse) </span>because it takes a little bit of time for the pressure to transmit through the body, as the finger is not on the heart (if it was there would be no delay)
elements are pure substances composed of only one kind of atom. An example that is present in the body is oxygen which is present in the lungs and also in the blood. Compounds are composed of different types of atoms which differ in ratio from one to another. an example is water. The two terms are different in structure and hence the properties.
Answer:
D
Explanation:
Fossils tell us where they came from.
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I would have to say skin or hair
Answer:
The researcher centred on the potential uses of biochar, charcoal primarily used for agricultural and to improve the quality of post mining sites.
A method called mountaintop removal was used by mining firms. This means that they remove rock and mineral deposits off the top of the mountain to gain access to within the coal seams. The resulting soil is infertile and strongly acidic.
The compacted soil after mine proves harder to bring seed into the soil.
The researchers try to use biochar to help reforest the soil at the post-mining site. Before it was reseeded and replanted, they got permission to add a layer of biochar to a post-mining site. the team created
“planting cells” of biochar‐enhanced soil on the post‐mining site and that showed improvment in the sapling growth.