radioisotope

n radioactive form of an element, used in medicine, industry, etc to study the path and speed of substances through bodies and objects 放射性同位素.

radio, radio astronomer, radio astronomy, radio car, radio cab, radio frequency, radio telescope, radio transmitter, radio-, radio-astronomer, radio-carbon, radio-controlled, radio-frequency, radio-therapist, radio-therapy, radioactive, radioactivity, radiogram, radiograph, radiographer, radiography, radiologist, radiology, radish, radium, radius, radon, RAF, raffia, raffish, raffishly, raffishness, raffle, raft, rafter, raftered, rag, rag-and-bone man, rag-bag, ragamuffin, rage,