These greenhouse gases are trapping the heat inside the atmosphere. When more of these gases are released, it contributes to global warming and the melting of many polar areas that could potentially cause a natural disaster in the future.
Answer: Option B
Explanation: The first line of defense acts a barrier and does not allows the foreign materials to enter inside the body. It includes chemical and physical barriers that are always ready to protect the body from infection.
Example: Skin and mucous membrane.
Skin is largest organ and it acts as a barrier between pathogens and human body. It acts a waterproof material and the pathogens cannot get inside through skin unless the skin is broken.
Mucous membranes also acts as first line of defense and breaks the cell wall of many bacteria entering through the openings of the body.
So, skin and mucous membrane are the first line of defense.
The law states that matter is conserved. It is not randomly llost or gained, but transformed.
This holds true because when a glass of water is left out over night, the water evaporates. The water doesn't magically disappear. It is just transformed into water vapor.
Answer:
I'm not really certain about this but my answer would be (a)