The stratum corneum is the most superficial layer of the epidermis...it's the one that's exposed to the environment. That's why it's waterproof!
I believe the answer should be solar
There are often not more than one or two independent variables tested in an experiment, otherwise it is difficult to determine the influence of each upon the final results. There may be several dependent variables, because manipulating the independent variable can influence many different things.
Since the other answer got deleted, i'll just answer it for you.
a sinoatrial node is the main pacemaker that begins each heartbeat located in the junctions of superior vena cava and the right atrium. It signals from the node that spread through the atria and determines the heart rates.
Answer:
Sustainable use of the environment
Explanation:
Be it the ecosystem or the food you eat, if you just take up whatever you need instead of over exploiting the resources, another life can benefit from it. The relationship we need to form with our environment should be mutualism or commensalism but not parasitism.