13. Which of these statements about particulate matter less than 2.5 microns in diameter is true? A. They can cause heart and lung disease.

B. They're produced from nitrogen gas (N.).

C. They're less of a threat than particulate matter that's 10 microns in diameter

D. They're the size of a human hair.

Q: a: in sexually reproducing animals, once fertilization of the egg takes place, the exists as a single cell until cell division begins

45 points how are people today being protected from tsunamis? earthquake data is analyzed to detemrine if a tsunami is likely, and if so, warnings are sent out. areas in tsunami risk zones are no longer heavily populated. radar is used to measure wave heights regularly. meteorologists study the winds to determine if wave heights will be large.

Imagine a self-reactive t cell that has not undergone clonal deletion in the thymus (that is to say, it has escaped central tolerance). if it encounters self antigen in the absence of an infection or inflammation, what will happen to this self-reactive t cell? (select two answers) (a) the t cell undergoes clonal expansion. (b) the t cell gains effector functions. (c) the t cell undergoes apoptosis. (d) the t cell becomes activated. (e) the t cell becomes anergic.