Germ theory that states that microorganisms, which are too small to be seen without the aid of a microscope, can invade the body and cause certain diseases. in the late 1800's this theory lead to a simple practice that saved thousands of lives in hospitals throughout the country from post-operative infections. this practice was

Which best explains how a heat pump can heat a room? cold air from the house is moved through pipes, where it absorbs thermal energy. warm air from outside is pushed into the house to replace the cold air. combustion warms the air when chemical energy is transferred to thermal energy. fuel is used to move a piston, which pushes warm air into the house.

Below, the levels of organization in a multicellular organism are shown from least to most complex. which level of organization can be described as several different types of tissues working together to perform a common task?

Explain how the political influence of african americans leaders became weaker.