Our energy supply comes mainly from fossil fuels, with nuclear power and renewable sources rounding out the mix. These sources originate mostly in our local star, the Sun. Electricity falls into its own category because it's an energy carrier and not a primary source.
I believe the answer is A
The cells, organelles, and the tissues of the body are measured in micrometers. The size of the cells, tissues, and various organelles are very small. Majority needs the help of microscope to be seen. Therefore, the larger units of the metric system cannot be used to measure their sizes. Hence, the smaller unit, such as the micrometer is used for their measurement purpose.
The given blank can be filled with micrometers.
The population must be infinitely large!
Hope this helps!
