They are saying that every theory can eventually be changed a bit due to further research. It does not mean the theory is bad, just that it can become better.
Answer:
A. Protein Spikes
Explanation:
A viruses are defined as the quintessential parasites in the living world. They are a chain of the nucleic acids that lives in a host cell. Without the host cell, all the viruses cannot carry out their life sustaining activities or functions. They are always housed in a protein layer or a protein coat. All the viruses contains the RNA or the DNA. The protein spikes which is on the outside of a virus are "sticky" and they are attracted to the specific molecules of the outside of an animal cells.
Answer:
Explanation:
Studies indicate that mining is one of the most perilous occupation in the world in terms of injuries and fatalities, and also due to the long term health effects associated with it. Long term effects include respiratory problems such as pneumoconiosis, asbestosis, and silicosis.
