【单选题】Design of all the new tools and implements is based on careful experiments with electronic instruments. First, a human' guinea pig' is tested using a regular tool. Measurements are taken of the amount...
A.
Electronic instruments and a regular tool.
B.
A human' guinea pig' and regular tool.
C.
Electronic instruments and a human' guinea pig'.
D.
Electronic instruments, a human 'guinea pig' and a regular tool.