You suspect that incorrect voltage is provided to a power supply. What tool should you use to test this?

What object oriented feature can we use to have a single test program, with one set of method calls in which the user can decide which bag implementation (array- or link-based) needs testing?

a. copy constructor b. polymorphism c. toVector d. the case statement

Class FontMetrics declares methods that can be used to obtain the following font metrics ________.

a. ascent, descent and height b. ascent, descent and leading c. height and leading d. All of the above.