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.
I believe the answer is angiosperms
Answer:
Las montañas generan sombre y brisa, mientras que que en una pradera que es casi llano el calor se acumula en el suelo pero el problema es la de forestación que provoca que las arboles que actuaban como las montañas dañen el entorno secando el fresco y húmedo suelo causando problemas con el ambiente
