What is the correct order for the evolution of these animal groups?

Fish-> amphibian-> reptile-> mammal
Mammal-> fish-> reptile-> amphibian
Mammal-> amphibian-> fish-> reptile
Fish-> reptile-> amphibian-> mammal

Which of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic

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 far away is the nearest black hole from earth?