Otters are from keystone species from the subfamily of Lutrinae. Lutrinae is a branch of Weasel. The actions of the humans that can ensure that the sea otter will continue their function in the environment would be to establish in the Atlantic ocean a sea otter wildlife refuge and also pass laws to regulate the hunting of such species.
Answer:
Your heart changes its rate depending on the activity, so that it can carry blood to your muscles, and therefore it needs to beat stronger if you are performing some exercise, or not so strong if you are sleeping, for example.
Explanation:
Your heart is continuously beating to keep blood circulating throughout your body.
So, here it is why your heart changes its rate: Its rate changes depending on your activity level; it is lower while you are asleep and at rest and higher while you exercise to supply your muscles with enough freshly oxygenated blood to keep the functioning at a high level.
And how: depending on your activity level, your heart has to pump enough blood to your muscles. Blood carries needed oxygen and other nutrients. Muscles need more blood sugar than any other tissue especially when working hard. To supply your muscles with oxygen your heart needs to beat faster, and this builds up your heart muscles.
C. Solar energy's whole purpose it to reduce pollution in the air that fossil feuls do not. The answer cannot be A. B. or D. because 1. it is expensive 2. it can only be used during the daytime. It is a SOLAR panel. and 3. like is said earlier it is not free.
