Answer:
First, it transports blood with oxygen and nutrients to cells all over the body. Second, it picks up waste products from the cells to be transported out of the body, and it takes the deoxygenated blood back to the lungs so it can regenerate.
C.there is no relationship between metabolic rate and body temperature.
In the scientific method first of all is you need to identify the problem, the problem to your question is why does the dog circle its bed before lying down. Second is the observation to gather some data, you need to observe the dog if what could be the possibility the the dog may do that action. The third is the pre hypothesis, you need to came up with an idea why does the dog do such and action for example the needs to find a correct spot to make itself comfortable and lastly the hypothesis, this should answer to your question or your problem. So my hypothesis is that dogs are one of the animals that are those difficult to find a place to sleep and some of that kind of animals are cat, before they lay on their bed, they have to circle to find a spot that could fit its body to be more comfortable when the dog sleep
Answer: muscle contraction of sustained force resulting from repeated action potentials. (Option A)
Explanation: Tetanus is also called physiologic tetanus. Tetanus refers to the contraction of the muscle, which is established when the motor nerve that supply nerves to a skeletal muscle produces action potentials at a very high degree.
However, tetanic contraction is usually a normal process (such as when carrying a heavy box). Also, muscles can be shorten, lengthen or remain constant length during tetanic contractions.