B coriolis effect warmer water rises as it gets cold it sinks back down
bacteria in food can be killed by many means such as:
a) Pickling. for example food is pickled as bacteria cannot live in very acidic conditions.
b) Boiling. boiling water or liquids can help kill bacteria present in them.
c) Using preservatives can also help
d) Immersing food in salt or sugar solutions is also an other way
As newer rock layers form, they overlap with the ones with the pre-existing ones. Therefore, when looking for older rock layers, we would look for the ones that are deeper beneath the surface of the earth. On the other hand, newer rock layers are found at the top. This is also observed in the fact that oil rigs dig very deep into the ground to access the layers that are millions of years old.
Https://www.ncbi.nlm.nih.gov/pubmed/8300084
This might help
