Which question is not answered by the article?A why don’t people in Russia and other countries smile a lot?
B how did researchers learn that smiling is common in countries with more immigration?
C where in the world do people smile a lot, other than in the United States?
D why was it hard for people who came to the u. s in the early 1900s and did not speak English?

The chart shows the marginal cost and marginal revenue of producing apple pies. what most likely will happen if the pie maker continues to make additional pies? the marginal costs will continue to rise, increasing the total cost, while the marginal revenue remains the same, decreasing the profit. the marginal costs will continue to fall, decreasing the total cost, while the marginal revenue remains the same, increasing the profit. the marginal costs will continue to rise, increasing the total cost, while the marginal revenue remains the same, increasing the profit. the marginal costs will continue to fall, decreasing the total cost, while the marginal revenue remains the same, decreasing the profit.

The difference between the lower class limits of adjacent classes provides the

In the modern world, many countries with kings or queens have evolved into constitutional democracies. in these countries, monarchs are mostly