The valves stop the blood from flowing backwards
These are some pronouns to help you!
<span>I, me, he, she, herself, you, it, that, they, each, few, many, who, whoever, whose, someone, everybody.
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It is who! :D
I hope this helps!
1) <span>flows of hot plasma in the convection zone
2) dark spots that appear sometimes because of </span><span>concentrations of magnetic field flux
3) "</span><span>a brief eruption of intense high-energy radiation from the sun's surface"
4) gas extended out from the corona but is attached to the sun and can reach great distances
5) large area in cocrona which is less dense and has cooler temperature they occur when "</span><span>the Sun's magnetic field is open to interplanetary space"</span>
I think it might be C or D
No, It can't be chemical because it has something to do with being mechanical, an example of a chemical change would be some thing like metal rusting or wood turning to ash after being burned.
