Which us president traveled to china to begin a new era of better relations between the two countries

Does anyone know the answers for these

[ou.01]which of these is the most likely use of an electromagnetic wave which has wavelength shorter than microwaves but longer than visible light? o heat food safely o neat food safely o take images of bones and teeth o transmit radio and cellular phone signals o take images of bones and teeth o transmit radio and cellular phone signals o detect the location of objects which emit heat

Can someone me? i need to have this done as soon as possible! i'm putting 20 points on this!