Answer:
One possible cause of persistent sadness could be depression
Explanation:
The answer is 800 meters.
You find this by taking the total distance of the first lap and doubling it. You could also find it by adding 400 meters to 400 meters, which would total at 800 meters
Bitterness, saltiness, and sourness could not be detected by the tip of the tongue
Common examples of this would be if you place your hand in extremely warm or cold water, and an immediate response of pulling out of the water or any fluid, is an example of this extreme response, other responses are what is done in everyday, like being thirsty or hungry etc.
These behaviours are shared by all organisms even the most simple ones.