A. external
These types of signals are observed when there is a cut on the body. The epidermal cells lose contact with one another and divide faster until they are in contact once again. After they come into contact, division slows down again.
Answer:
Air Pressure
Explanation:
Air pressure is the only option here related to weight. And Air Pressure does get lower the higher the airplane goes.
The cautions that can be given to the friend include the following:
Eating foods from different sources is very advantageous because it ensures that one gets all the necessary food nutrients that are needed for proper growth and development. Getting the necessary food nutrients on the other hand will boost one's immunity and enable one to develop resistance to diseases. Restricting one's food to a limited type of food is very bad and can have fatal consequences.
It also plays a key role in shaping organic molecules. Carbon<span> is very </span>important<span> to the chemistry of living things, mainly because of the versatility of structures it can form with itself and with other atoms</span>
