Answer:
Earth's atmosphere filters out harmful radiation from the sun.
Explanation:
The sun is earth's star and sunlight helps light up and warm the earth and also helps in the process of photosynthesis. Sunlight on the other hand, produces harmful rays called Ultraviolet radiation or UV rays.
These ultraviolet radiation is dangerous to our skin and ultimately our body as a whole. Fortunately for us, the earth's atmosphere has a protective layer called the Ozone layer. The Ozone layer serves to filter out and block the harmful ultraviolet radiation and prevent it from reaching the earth, thereby protecting us.
Sadly though, the Ozone layer is getting depleted by human activities which emit harmful gases like carbon dioxide into the atmosphere. Activities such as oil drilling, automobile emissions, destruction of forests etc. These activities affect the Ozone layer leading to it's gradual disappearance and letting in the harmful UV rays. A phenomenon referred to as global warming.
All living organisms are composed of cells. Multicellular organisms (example: humans) are composed of many cells while unicellular organisms (example: bacteria) are composed of only one cell. Cells are the basic unit of structure in all organisms.
The answer is A: least explosive
Answer: Frontier attitude
Continuous cell lines can be maintained through an indefinite number of generation :)