Answer:
Mechanical barriers — which include the skin , mucous membranes , and fluids such as tears and urine — physically block pathogens from entering the body. Chemical barriers — such as enzymes in sweat , saliva , and semen — kill pathogens on body surfaces.
Answer:
D. unnatural scream
Explanation:
The Bigfoot is a an animal around there's lot of debate, as there are thousands of sightings, but not conclusive proof that it actually exists, thus it falls into the category of mythological creatures for the time being. This creature has been described by thousands of people that claim to have seen it or hear it, and the descriptions are pretty much the same, very tall, hominid-like, bipedal, dark fur, very quick, and terrifying. Something else that is a specific feature of the creature is the sounds its make, as everyone has said that it produces incredibly powerful unnatural sounding scream. People have said that they have frozen from fear after hearing those sounds, and that whenever that sound occurs all other animals run away frightened in the opposite direction.
