Why is gold and silver most common metals used in making jewelry

Gold and silver are the metals which are malleable,ductile and lustrous .

They are noble metals , noble metals are not affected by acid , oxygen and atmosphere  etc.

Hence gold and silver are suitable for making jewelry.

dopamine..

"it was found that some people who were taking the drug l-dopa to raise their levels of dopamine were developing schizophrenic-like symptoms supporting research a strength of the dopamine hypothesis is that there are many studies which have shown support for the neurochemical explanation."

i think the answer is tomato juice? not entirely sure though