Which microscope will be most useful for quickly estimating the number of red blood cells and the patients blood sample

Are the earth's ocean floor and continents the same age geologically? why or why not?

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes

Which anatomical plane is the only one that could not show both the sternal region and vertebral region