<span>Sodium channels close when not occupied
</span><span>Sodium ions diffuse through and enter the cell.
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Then they leave the cell.
The sodium diverts in the cell layer have receptor locales for acetylcholine.
As any other ancient civilization, the Sumerians were traders as well. And they had a few good reasons to do this.
Because they traded, their trading partners were less likely to attack them, because it would hurt their economy as well. Furthermore, they didn't produce everything they needed and traded those goods with goods which they produced too much of.
And lastly, through trade they could also get exotic goods which they would have never gotten otherwise.
For an organism to function properly all the physiological factors should be favorable. These physiological factors include water level, pH, temperature etc. To perform the basic function of the life, it is important to maintain the physiological parameter in a particular range.
In case, these physiological parameters are not balanced, then the body of the organism does not perform well and causes illness.
So, the first blank can be filled with temperature and the second blank can be filled with range.
<span>B. The overuse of antibiotics. </span>Antibiotics have tremendously helped in in treating infectious diseases but throughout the years, overuse of antibiotics has also been found to contribute in the emergence of antibiotic-resistant diseases, which makes all of us vulnerable because of the lack of treatment for these new strains.