Why do the symptoms of certain viral infections occur after having disappeared for a period of time?

Of seawater increases with decrease in the temperature. therefore, the cold water sinks to the deeper layers at the bottom

At which location in earth’s interior does the top density continue to increase as thickness decreases?

(select all the correct choose each statement that is scientific. - the opinions of randomly selected participants in a survey prove the idea that global temperatures are not increasing on earth. - the universe's average temperature and rate of expansion support the idea that it began as one super-dense and hot mass 13.8 billion years ago. - ocean tides are caused by the uneven gravitational pulls of the moon and sun on different parts of earth. - human life is more valuable than other forms of life on earth because humans are more intelligent than other organisms.