If a ramp to the top of a 30 meter building at a construction site has a mechanical advantage of 4, how long must the ramp be?

Which term refers to the total dollar value of the goods and services produced in a country in a year?

Which number represents a basic ph, 4 or 9? numerical answers expected! answer for blank 1: i'll give

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.