What best explains why a person can become sunburned by spending too muk O Sunlight is an electromagnetic wave that gains energy as it travels through air to
O Sunlight is an electromagnetic wave carrying energy that is absorbed by the skin
O Sunlight is a mechanical wave that vibrates the skin particles to produce heat.
Sunlight is a mechanical wave, and its frequency matches the natural frequency

The business cycle is the periodic but irregular up-and-down movement in economic activity, measured by fluctuations in real gross domestic product (gdp) and other macroeconomic variables. a business cycle is typically characterized by four phases—recession, recovery, growth, and decline—that repeat themselves over time. economists note, however, that complete business cycles vary in length. the duration of business cycles can be anywhere from about two to twelve years, with most cycles averaging six years in length. some business analysts use the business cycle model and terminology to study and explain fluctuations in business inventory and other individual elements of corporate operations. but the term "business cycle" is still primarily associated with larger (industry-wide, regional, national, or even international) business trends.