T cells. When HIV arrives in the lymph nodes – around 24 to 48 hours after exposure – they activate other immune cells, such as CD4 t-cells, HIV's primary target.
<span>The feature of an experiment that is changed from one treatment to the next is referred as a variable. </span>
Vehicle exhaust fumes are also a threat to our air supply of clean air. It is means of transportation for a majority of the population whether it is a personal car or a ride on public transportation. It produces carbon dioxide and other greenhouse gases that keep heat trapped in the earth’s atmosphere.
The sentences that make sense are "Volatile liquids are flammable" and "Liquids burn easily."
