In a health context, gold is "helpful". It's entirely inert -- it doesn't do anything in your body chemically. It doesn't have too many medical uses, however. Most of these are dental.
If you need help I recommend you type in the specific question you need help with
it can be helpful or harmful
sometimes they are helpful and harmful.
Bacteria can be both harmful and helpful
Sandpaper is both helpful and harmful.
they are helpful not harmful to plants
harmful
helpful
Helpful
helpful
Depends on what part of "harmful" or "helpful" you are referring to.
Harmful bacteria will harm you. Helpful bacteria will help you.