In the spiral model of software development, the primary determinant in selecting activities in each iteration is ________.
The cyclomatic complexity metric provides the designer with information regarding the number of ________.
The incremental model of software development is ________.
The surface integral \( \int_S x^2 \, dS \) over the upper hemisphere
\[ z = \sqrt{1 - x^2 - y^2} \]
with radius 1 is ..........