Persons with HIV are most vulnerable to opportunistic infections when the number of CD4 cells fall below ________ cells per cubic mm

The minimum intensity of physical stimulation required to produce any sensation at all in a person is the _______

a. absolute threshold b. difference threshold c. minimum threshold d. noticeable threshold

Which is the most studied social dialect of standard American English?

A) Hispanic English B) Northern English C) Asian English D) African American English