The Sun is a main - sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. In its core, the Sun fuses 620 million metric tons of hydrogen each second.
The answer is steamboats! The first steamboat came year 1807 and was invented by John Fitch:)
<span>D. Overcrowding and destruction of rain forests</span>
The correct answer is - B. deciding how many cans of vegetables to store at a warehouse.
The quaternary economic activities do not involve physical involvement into the production, trade, or storage of the products, but instead, this type of economic activity is performed strictly by using ones brain, thus making decisions and plans that are going to be performed by the workers in the primary and secondary (occasionally in the tertiary) economic layers.
Wind is the answer to this.
