The pump in a circulatory system is called the Choose...
. In vertebrates, its chambers include at least one
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, which receives the blood, and at least one
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, which pumps the blood to other body organs.

Which statement correctly describes other ways in which nebulae and stars are different? a. a star always has a higher density than a nebula. b. stars can form inside a nebula but a nebula can never be produced by any star. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star. reset submit