"Changing water salinity" is the most significant challenge for organisms that live in estuaries.
<u>Answer:</u> Option D
<u>Explanation:</u>
For estuaries, alkalinity levels are usually the maximum at a river's mouth where the ocean water falls for, and the minimum upstream where freshwater falls in. Although salinity vary throughout the tidal cycle. In estuaries, salinity rates usually decrease in spring as snow melt and rain raises the freshwater flow from streams and groundwater.
It influences the chemical environments within the estuary, especially the dissolved oxygen (DO) levels in the water. The level of oxygen that would get dissolved in water or its solubility get declined when the alkalinity rises.
Hello,
Average speed is total distance divided by total time. From the problem, our total distance is given as 500 kilometers and given time is 5 hours. Therefore, the average speed is:

Therefore, the average speed is 100 km/h. Please let me know if you have any questions!
Answer:
i think its C hope this is rhight have a good day
Explanation:
Answer:
100 ÷ 9.58 = 10.44 (approximate answer)
Honestly I don’t really know in my opinion