Gradual changes in the frequency of diseases over long periods are known as SECULAR TIME TRENDS. For example, the rate of mortality in USA due to coronary heart diseases over a period of time. Onset of puberty in girls is also a secular time trend.
Secular time trend is also referred as Secular Variation and Secular Drift.
Answer:
An old penny rusting
Explanation:
A penny forming rust is the penny being chemically altered and changing form as opposed to dissolving sugar in water, which is still sugar, just mixed with water. It doesn't change the chemical makeup of the water or sugar.
Answer:
The function of the appendix is unknown. One theory is that the appendix acts as a storehouse for good bacteria, “rebooting” the digestive system after diarrheal illnesses. Other experts believe the appendix is just a useless remnant from our evolutionary past.
Answer:
D
Explanation:
Bacteria, air, animals, plants
