According to the text, the example of attitudes toward smoking in the u. s. demonstrates the notion that

Smoking has become more addictive because of the chemicals. It also notifies that the world is full of pollution.

the part of the earth that is best reflected on a map is the surface. maps reflect borders of countries or territories as well as physical features like mountains.

explanation:

answer; researchers typically cannot control people's sexual behaviors as would be necessary in an experiment;