In addition to taste buds, what should also guide our eating habits?

Food doesn't have flavor without saliva if that's what you're asking. However, what should guide your habits is how you personally feel and what is healthy. If you feel hungry, go for it, but make sure you're eating a healthy amount. Not too much but not too little.

the correct answer is 4 (giveaways to the public)

something that is given away or gave out for free. an occasion at which things are given away to free. something that is evident or obvious; something that uncovers a mystery.

it could be be in a form of a lucky draw as well. these the company events gather more audience for their pr and it also increases their ratings as well. this is a way to attract more customers towards themselves.

with out the ancient ppl we wouldnt have medicine beacuse they taught us.