Humans can observe radiations with wavelengths from _____ nm to _____ nm. July 27, 2024July 27, 2024 CSS MPT Everyday Science MCQs FPSC NTS PPSC Past Papers Test Questions (A) 200, 400(B) 200, 500(C) 400, 600(D) 400, 700 The answer is: (D) 400, 700