A.234U B.235U C.238U D.232Th E.226Ra
A.距探傷機焦點1m處1mGy/h B.距探傷機表面1m處1mGy/h C.距探傷機焦點1m處2.5mGy/h D.距探傷機焦點5cm處25mGy/h E.距探傷機焦點1m處5mGy/h
A.1/10 B.1/30 C.1/50 D.1/100 E.1/200