Which rays are mainly used to find out invisible handwritings, forged documents and fingerprints handwritings, forged documents and fingerprints?
A. Ultraviolet rays
B. Infrared ways
C. Beta rays
D. Gamma rays
Answer:A
Which rays are mainly used to find out invisible handwritings, forged documents and fingerprints handwritings, forged documents and fingerprints?
A. Ultraviolet rays B. Infrared ways C. Beta rays D. Gamma rays