Which of the two types of immu-
nity requires white blood cells?
explain.

The acquired or adaptive immunity requires white blood cells.

Explanation:

Acquired immunity acts by destroying the foreign particles with the help of white blood cell called lymphocytes. The lymphocytes – T cells and B cells activates the acquired immunity system.  

The T-cells activates mediated immunity, where they directly destruct the problematic cells like tumor cells. This cell-mediated action is proceeded by different T cells – cytotoxic, suppressor, and helper T cells.  

The B-cells activate humoral immunity by triggering antibody production against specific antigens and by signaling T cell activation. This antibody-mediated action is undertaken by plasma and memory B cells .

answer-

the statement that f(x) = |x+a| + b has exactly one x-intercept is sometimes correct.

solution-

it solely depends on b, whether the function will have one or two or zero x intercept.

this plot of the given function, f(x) = |x+a| + b will be the basic absolute value graph i.e v shape, with vertex translated to (-a, b), instead of origin.

1-   if b is zero, the graph will have exactly one x-intercept, at x= -a

2- if b is positive, the whole graph will be above the x-axis, hence it will have no x-intercepts.

3- if b is negative, the graph will be below the x-axis, hence it will have two x-intercepts.

∴ the statement is sometimes true.