Answer:
Viruses and prions are considered microbes.
Some microbes are visible to the naked eye.
Explanation:
Microbes are the tiny organisms that can not be seen with unaided eyes. However, this does not hold true for all and some microbes like <em>Epulopiscium fishelsoni</em> can be seen with unaided eyes. Bacteria, viruses, protozoans, and prions are some of the microbes. Viruses are the microbes that have a protein coat around their genetic material. Prions are proteins that can cause infections. Prions do not have any genetic material.
Answer:
a device for collecting and measuring rain as it falls
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.