Earth can be considered as a closed system, since it only receives sunlight (energy), while the overall mass stays constant, without (almost) any exchange from space. Another example of a closed system is a saucepan or frying pan, on a stove, when its lid is closed.
Answer:
Reductions in Child Mortality. ...
Vaccine-Preventable Diseases. ...
Access to Safe Water and Sanitation. ...
Malaria Prevention and Control.
Explanation:
The average life expectancy of a child born in the U.S. in 1900 was 50 years. By 2010, this number had increased 60% to 80 years.1 Biomedical, epidemiological, and behavioral research combined with public policy played a major role in this gain. Below are major public health milestones of the last 100 years
Marble, Roman copy after a Greek original from ca. 430 BCE. The Athenian democracy of Cleisthenes<span>and </span>Pericles<span> was based on freedom, through the reforms of Solon, and equality (isonomia), introduced by </span>Cleisthenes<span> and later expanded by Ephialtes and</span>Pericles<span>.</span>
Do you have options I can choose from?
