The antibodies to the HIV virus may take up to three months to appear in the blood of the infected person.
Therefore, the second blood test is necessary three months after a person thinks that he/she has been exposed to HIV to check the presence of these antibodies and confirm whether the person is infected or not.
The answer is Permian-Triassic extinction.
The Permian-Triassic extinction was 252 million years ago. It is known as The Great Dying because about 95% of all species died out due to environmental changes (volcanic eruptions, dry climate, melting of ice sheets, etc). This is also the only event in which many insect species wiped out.
True true true true true true maybe
