【填句补文】Gang Xiao and Ben Schrag at Brown University, visualize the current by measuring subtle(细微的) changes in the magnetic field of an object and ________.

【填句补文】Gang Xiao and Ben Schrag at Brown University, visualize the current by measuring subtle(细微的) changes in the magnetic field of an object and ________.

A.to shrink it to the size of a desktop computer

B.to make it capable of measuring very weak changes in magnetic fields

C.as well as revealing microscopic defects in anything from aircraft to banknotes

D.converting the information into a color picture showing the density of current at each point

正确答案是D