In international trade, an exchange rate is a. a way to record a nation’s imports and exports b. an agreement between nations to reduce trade barriers c. a chart for keeping track of prices on a stock exchange d. a number that is used to show the value of one currency compared to another

Option D. a number that is used to show the value of one currency compared to another

Explanation:

An exchange rate represents the value by which one currency is larger or smaller to any other currency in terms of economic value.

It can also be stated as the numeric value which represents how much is the currency of country in terms of the currency of other nation.

For example - one US dollar is equal to 68.37 Indian rupee.

Thus, option D is correct

this protocol provides a detailed procedure for total protein extraction for western blot analysis from achieved samples following trizol isolation of rna.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.