The "Spanish" influenza pandemic of 1918–1919, which caused ≈50 million deaths worldwide, remains an ominous warning to public health. Many questions about its origins, its unusual epidemiologic features, and the basis of its pathogenicity remain unanswered. The public health implications of the pandemic therefore remain in doubt even as we now grapple with the feared emergence of a pandemic caused by H5N1 or other virus. However, new information about the 1918 virus is emerging, for example, sequencing of the entire genome from archival autopsy tissues. But, the viral genome alone is unlikely to provide answers to some critical questions. Understanding the 1918 pandemic and its implications for future pandemics requires careful experimentation and in-depth historical analysis.
<u>Answer</u>: The energy source that generates wind is actually the sun.
<u>Explanation</u>: The uneven heating of the Earth's surface by the sun gives rise to differences in atmospheric pressure. Areas such as deserts will warm the air masses above much more. As air is heated, it has a lower density as it expands and thus will form a point of low atmospheric pressure. The opposite situation applies for high pressure areas.The air movement from areas of high pressure to areas of lower pressure is what we call wind.
The two substances are rock (molten and solid) and metal (solid + liquid).
Layers of the earth from the outside in:
1. crust. hard rock/dirt/ground. Shell
2. mantle. melted rock and stuff. Egg white
3. core. Outer core - liquid. Inner core- solid. Nickle and iron. Yolk
Answer:
it will be the answer B. scientists discover new elenents.
