Answer:
The correct answer is biological.
Explanation:
When any pathogen invades the body, it has to pass several lines of defence. The first barrier is the skin and mucous membrane which is a physical and chemical barrier. The second line of defence is the non-specific response by macrophages, neutrophils and interferon. After crossing these two barriers the third line of defence comes into action in which, the B- cells and T-cells act specifically on the pathogen and destroy it.
Answer:
Burning sugar results in a chemical reaction
Explanation:
Flammability, odor, and density are just a few examples of characteristic properties of a substance. A chemical reaction occurs when molecules interact with one another and the molecules change. For example burning sugar results in a chemical reaction because the properties of cube B changed when it was burned. This change in solubility shows that cube B must be a different substance than cube A because of the chemical reaction that occurred when cube B was burned.
1. Condensation is the process in which gas changes into a liquid when it touches a cooler surface.
2. Condensation is an important part of the water cycle. It is the opposite of evaporation.
Answer:
the later stages are small and the tool materials are of better quality than the previous stages.
Explanation:
The stone scrapers and the choppers found at the site of Zhoukoudian points out the fact that Peking men devised several tools for various purposes and to accomplish different tasks. The stones and the bones used to make the tools used to be charred by using the fire. This also indicates that the Peking men had discovered the uses of fire and they used fire for various activities.
