In maintaining the large land empire of russia, what was arguably the main difficulty?

a. ethnic divisions
b. inexperienced leaders
c. lack of industrialization
d. lack of natural resources

How do ratio scale and diagrammatic scale work

Lactase is essential for digesting lactose in milk. this enzyme is specific for this sugar. why? molecules and active sites vary in size; only properly sized molecules can fit.there is a precise compatibility between the active site and the lactose molecule.specificity refers to the action of the enzyme, such as hydrolysis, and relatively few molecules can be hydrolyzed.reaction-specific enzymes assume a fit by folding around the most numerous substrate molecules.

How do disease caused by bacteria and disease caused by viruses react to antibiotics