41. An operating system:

A. can help reduce software development time
B. provides ability for other programmers to understand the software structure
C. is useless in most control applications
D. All of the above
E. None of the above

42. A programmable controller:

A. can be used on more than one machine during its lifetime.
B. can be reprogrammed in the field
C. requires considerable training before it can be used
D. (a) and (b) above
E. None of the above

43. A LISP environment consists of a language, a programming environ¬ment, and:

A. random-access storage
B. a processor
C. a large address
D. a set of functions
E. None of the above

44. What Is a process variable?

A. A manipulated variable
B. A controlled variable
C. A process parameter that changes value
D. All of the above
E. None of the above

45. Time proportioning control:

A. can be used on a PM550 programmable process controller
B. is less efficient than normal PID control
C. cannot use a TM990 micro¬computer
D. a and b above.
E. None of the above