Answer:
C
Explanation:
Keystone species is the sea otter. Sea otters, playing a critical role in containing the urchin populations, prey on urchins and thus control the numbers of kelp grazers to maintain the forest.
Remember, keystone species is most often a top level predator in an ecosystem.
Answer:
The air pollution in china decreases due to less usage of transportation and shutdown of industries.
Explanation:
From December to march, transportation and industrial work is greatly affected due to the corona virus. Due to reduction of activities in both transportation and industries, there is a lot of decrease occurs in the air pollution. We know that smoke produce by vehicles and industries are the main cause of pollution so that's why air pollution decreases between December to march..
the layer on the top. the layer with the most minerals.
There is one choice missing from this question:
<span>a. narcoleptic fits
b. nightmares
c. apnea episodes
d. night terrors*
The correct answer is "night terrors". Night terrors are intense feelings at the first half of non-REM sleep that is characterized by fear, horror, trembling, shaking. Night terrors are different from nightmares as there are physical effects carried out from night terrors upon waking up such as screaming, crying, and sudden movements.</span>
